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.venv/lib/python3.12/site-packages/sympy/categories/baseclasses.py

@@ -0,0 +1,978 @@
+from sympy.core import S, Basic, Dict, Symbol, Tuple, sympify
+from sympy.core.symbol import Str
+from sympy.sets import Set, FiniteSet, EmptySet
+from sympy.utilities.iterables import iterable
+
+
+class Class(Set):
+    r"""
+    The base class for any kind of class in the set-theoretic sense.
+
+    Explanation
+    ===========
+
+    In axiomatic set theories, everything is a class.  A class which
+    can be a member of another class is a set.  A class which is not a
+    member of another class is a proper class.  The class `\{1, 2\}`
+    is a set; the class of all sets is a proper class.
+
+    This class is essentially a synonym for :class:`sympy.core.Set`.
+    The goal of this class is to assure easier migration to the
+    eventual proper implementation of set theory.
+    """
+    is_proper = False
+
+
+class Object(Symbol):
+    """
+    The base class for any kind of object in an abstract category.
+
+    Explanation
+    ===========
+
+    While technically any instance of :class:`~.Basic` will do, this
+    class is the recommended way to create abstract objects in
+    abstract categories.
+    """
+
+
+class Morphism(Basic):
+    """
+    The base class for any morphism in an abstract category.
+
+    Explanation
+    ===========
+
+    In abstract categories, a morphism is an arrow between two
+    category objects.  The object where the arrow starts is called the
+    domain, while the object where the arrow ends is called the
+    codomain.
+
+    Two morphisms between the same pair of objects are considered to
+    be the same morphisms.  To distinguish between morphisms between
+    the same objects use :class:`NamedMorphism`.
+
+    It is prohibited to instantiate this class.  Use one of the
+    derived classes instead.
+
+    See Also
+    ========
+
+    IdentityMorphism, NamedMorphism, CompositeMorphism
+    """
+    def __new__(cls, domain, codomain):
+        raise(NotImplementedError(
+            "Cannot instantiate Morphism.  Use derived classes instead."))
+
+    @property
+    def domain(self):
+        """
+        Returns the domain of the morphism.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> f.domain
+        Object("A")
+
+        """
+        return self.args[0]
+
+    @property
+    def codomain(self):
+        """
+        Returns the codomain of the morphism.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> f.codomain
+        Object("B")
+
+        """
+        return self.args[1]
+
+    def compose(self, other):
+        r"""
+        Composes self with the supplied morphism.
+
+        The order of elements in the composition is the usual order,
+        i.e., to construct `g\circ f` use ``g.compose(f)``.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> g * f
+        CompositeMorphism((NamedMorphism(Object("A"), Object("B"), "f"),
+        NamedMorphism(Object("B"), Object("C"), "g")))
+        >>> (g * f).domain
+        Object("A")
+        >>> (g * f).codomain
+        Object("C")
+
+        """
+        return CompositeMorphism(other, self)
+
+    def __mul__(self, other):
+        r"""
+        Composes self with the supplied morphism.
+
+        The semantics of this operation is given by the following
+        equation: ``g * f == g.compose(f)`` for composable morphisms
+        ``g`` and ``f``.
+
+        See Also
+        ========
+
+        compose
+        """
+        return self.compose(other)
+
+
+class IdentityMorphism(Morphism):
+    """
+    Represents an identity morphism.
+
+    Explanation
+    ===========
+
+    An identity morphism is a morphism with equal domain and codomain,
+    which acts as an identity with respect to composition.
+
+    Examples
+    ========
+
+    >>> from sympy.categories import Object, NamedMorphism, IdentityMorphism
+    >>> A = Object("A")
+    >>> B = Object("B")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> id_A = IdentityMorphism(A)
+    >>> id_B = IdentityMorphism(B)
+    >>> f * id_A == f
+    True
+    >>> id_B * f == f
+    True
+
+    See Also
+    ========
+
+    Morphism
+    """
+    def __new__(cls, domain):
+        return Basic.__new__(cls, domain)
+
+    @property
+    def codomain(self):
+        return self.domain
+
+
+class NamedMorphism(Morphism):
+    """
+    Represents a morphism which has a name.
+
+    Explanation
+    ===========
+
+    Names are used to distinguish between morphisms which have the
+    same domain and codomain: two named morphisms are equal if they
+    have the same domains, codomains, and names.
+
+    Examples
+    ========
+
+    >>> from sympy.categories import Object, NamedMorphism
+    >>> A = Object("A")
+    >>> B = Object("B")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> f
+    NamedMorphism(Object("A"), Object("B"), "f")
+    >>> f.name
+    'f'
+
+    See Also
+    ========
+
+    Morphism
+    """
+    def __new__(cls, domain, codomain, name):
+        if not name:
+            raise ValueError("Empty morphism names not allowed.")
+
+        if not isinstance(name, Str):
+            name = Str(name)
+
+        return Basic.__new__(cls, domain, codomain, name)
+
+    @property
+    def name(self):
+        """
+        Returns the name of the morphism.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> f.name
+        'f'
+
+        """
+        return self.args[2].name
+
+
+class CompositeMorphism(Morphism):
+    r"""
+    Represents a morphism which is a composition of other morphisms.
+
+    Explanation
+    ===========
+
+    Two composite morphisms are equal if the morphisms they were
+    obtained from (components) are the same and were listed in the
+    same order.
+
+    The arguments to the constructor for this class should be listed
+    in diagram order: to obtain the composition `g\circ f` from the
+    instances of :class:`Morphism` ``g`` and ``f`` use
+    ``CompositeMorphism(f, g)``.
+
+    Examples
+    ========
+
+    >>> from sympy.categories import Object, NamedMorphism, CompositeMorphism
+    >>> A = Object("A")
+    >>> B = Object("B")
+    >>> C = Object("C")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> g = NamedMorphism(B, C, "g")
+    >>> g * f
+    CompositeMorphism((NamedMorphism(Object("A"), Object("B"), "f"),
+    NamedMorphism(Object("B"), Object("C"), "g")))
+    >>> CompositeMorphism(f, g) == g * f
+    True
+
+    """
+    @staticmethod
+    def _add_morphism(t, morphism):
+        """
+        Intelligently adds ``morphism`` to tuple ``t``.
+
+        Explanation
+        ===========
+
+        If ``morphism`` is a composite morphism, its components are
+        added to the tuple.  If ``morphism`` is an identity, nothing
+        is added to the tuple.
+
+        No composability checks are performed.
+        """
+        if isinstance(morphism, CompositeMorphism):
+            # ``morphism`` is a composite morphism; we have to
+            # denest its components.
+            return t + morphism.components
+        elif isinstance(morphism, IdentityMorphism):
+            # ``morphism`` is an identity.  Nothing happens.
+            return t
+        else:
+            return t + Tuple(morphism)
+
+    def __new__(cls, *components):
+        if components and not isinstance(components[0], Morphism):
+            # Maybe the user has explicitly supplied a list of
+            # morphisms.
+            return CompositeMorphism.__new__(cls, *components[0])
+
+        normalised_components = Tuple()
+
+        for current, following in zip(components, components[1:]):
+            if not isinstance(current, Morphism) or \
+                    not isinstance(following, Morphism):
+                raise TypeError("All components must be morphisms.")
+
+            if current.codomain != following.domain:
+                raise ValueError("Uncomposable morphisms.")
+
+            normalised_components = CompositeMorphism._add_morphism(
+                normalised_components, current)
+
+        # We haven't added the last morphism to the list of normalised
+        # components.  Add it now.
+        normalised_components = CompositeMorphism._add_morphism(
+            normalised_components, components[-1])
+
+        if not normalised_components:
+            # If ``normalised_components`` is empty, only identities
+            # were supplied.  Since they all were composable, they are
+            # all the same identities.
+            return components[0]
+        elif len(normalised_components) == 1:
+            # No sense to construct a whole CompositeMorphism.
+            return normalised_components[0]
+
+        return Basic.__new__(cls, normalised_components)
+
+    @property
+    def components(self):
+        """
+        Returns the components of this composite morphism.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> (g * f).components
+        (NamedMorphism(Object("A"), Object("B"), "f"),
+        NamedMorphism(Object("B"), Object("C"), "g"))
+
+        """
+        return self.args[0]
+
+    @property
+    def domain(self):
+        """
+        Returns the domain of this composite morphism.
+
+        The domain of the composite morphism is the domain of its
+        first component.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> (g * f).domain
+        Object("A")
+
+        """
+        return self.components[0].domain
+
+    @property
+    def codomain(self):
+        """
+        Returns the codomain of this composite morphism.
+
+        The codomain of the composite morphism is the codomain of its
+        last component.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> (g * f).codomain
+        Object("C")
+
+        """
+        return self.components[-1].codomain
+
+    def flatten(self, new_name):
+        """
+        Forgets the composite structure of this morphism.
+
+        Explanation
+        ===========
+
+        If ``new_name`` is not empty, returns a :class:`NamedMorphism`
+        with the supplied name, otherwise returns a :class:`Morphism`.
+        In both cases the domain of the new morphism is the domain of
+        this composite morphism and the codomain of the new morphism
+        is the codomain of this composite morphism.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> (g * f).flatten("h")
+        NamedMorphism(Object("A"), Object("C"), "h")
+
+        """
+        return NamedMorphism(self.domain, self.codomain, new_name)
+
+
+class Category(Basic):
+    r"""
+    An (abstract) category.
+
+    Explanation
+    ===========
+
+    A category [JoyOfCats] is a quadruple `\mbox{K} = (O, \hom, id,
+    \circ)` consisting of
+
+    * a (set-theoretical) class `O`, whose members are called
+      `K`-objects,
+
+    * for each pair `(A, B)` of `K`-objects, a set `\hom(A, B)` whose
+      members are called `K`-morphisms from `A` to `B`,
+
+    * for a each `K`-object `A`, a morphism `id:A\rightarrow A`,
+      called the `K`-identity of `A`,
+
+    * a composition law `\circ` associating with every `K`-morphisms
+      `f:A\rightarrow B` and `g:B\rightarrow C` a `K`-morphism `g\circ
+      f:A\rightarrow C`, called the composite of `f` and `g`.
+
+    Composition is associative, `K`-identities are identities with
+    respect to composition, and the sets `\hom(A, B)` are pairwise
+    disjoint.
+
+    This class knows nothing about its objects and morphisms.
+    Concrete cases of (abstract) categories should be implemented as
+    classes derived from this one.
+
+    Certain instances of :class:`Diagram` can be asserted to be
+    commutative in a :class:`Category` by supplying the argument
+    ``commutative_diagrams`` in the constructor.
+
+    Examples
+    ========
+
+    >>> from sympy.categories import Object, NamedMorphism, Diagram, Category
+    >>> from sympy import FiniteSet
+    >>> A = Object("A")
+    >>> B = Object("B")
+    >>> C = Object("C")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> g = NamedMorphism(B, C, "g")
+    >>> d = Diagram([f, g])
+    >>> K = Category("K", commutative_diagrams=[d])
+    >>> K.commutative_diagrams == FiniteSet(d)
+    True
+
+    See Also
+    ========
+
+    Diagram
+    """
+    def __new__(cls, name, objects=EmptySet, commutative_diagrams=EmptySet):
+        if not name:
+            raise ValueError("A Category cannot have an empty name.")
+
+        if not isinstance(name, Str):
+            name = Str(name)
+
+        if not isinstance(objects, Class):
+            objects = Class(objects)
+
+        new_category = Basic.__new__(cls, name, objects,
+                                     FiniteSet(*commutative_diagrams))
+        return new_category
+
+    @property
+    def name(self):
+        """
+        Returns the name of this category.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Category
+        >>> K = Category("K")
+        >>> K.name
+        'K'
+
+        """
+        return self.args[0].name
+
+    @property
+    def objects(self):
+        """
+        Returns the class of objects of this category.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, Category
+        >>> from sympy import FiniteSet
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> K = Category("K", FiniteSet(A, B))
+        >>> K.objects
+        Class({Object("A"), Object("B")})
+
+        """
+        return self.args[1]
+
+    @property
+    def commutative_diagrams(self):
+        """
+        Returns the :class:`~.FiniteSet` of diagrams which are known to
+        be commutative in this category.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism, Diagram, Category
+        >>> from sympy import FiniteSet
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> d = Diagram([f, g])
+        >>> K = Category("K", commutative_diagrams=[d])
+        >>> K.commutative_diagrams == FiniteSet(d)
+        True
+
+        """
+        return self.args[2]
+
+    def hom(self, A, B):
+        raise NotImplementedError(
+            "hom-sets are not implemented in Category.")
+
+    def all_morphisms(self):
+        raise NotImplementedError(
+            "Obtaining the class of morphisms is not implemented in Category.")
+
+
+class Diagram(Basic):
+    r"""
+    Represents a diagram in a certain category.
+
+    Explanation
+    ===========
+
+    Informally, a diagram is a collection of objects of a category and
+    certain morphisms between them.  A diagram is still a monoid with
+    respect to morphism composition; i.e., identity morphisms, as well
+    as all composites of morphisms included in the diagram belong to
+    the diagram.  For a more formal approach to this notion see
+    [Pare1970].
+
+    The components of composite morphisms are also added to the
+    diagram.  No properties are assigned to such morphisms by default.
+
+    A commutative diagram is often accompanied by a statement of the
+    following kind: "if such morphisms with such properties exist,
+    then such morphisms which such properties exist and the diagram is
+    commutative".  To represent this, an instance of :class:`Diagram`
+    includes a collection of morphisms which are the premises and
+    another collection of conclusions.  ``premises`` and
+    ``conclusions`` associate morphisms belonging to the corresponding
+    categories with the :class:`~.FiniteSet`'s of their properties.
+
+    The set of properties of a composite morphism is the intersection
+    of the sets of properties of its components.  The domain and
+    codomain of a conclusion morphism should be among the domains and
+    codomains of the morphisms listed as the premises of a diagram.
+
+    No checks are carried out of whether the supplied object and
+    morphisms do belong to one and the same category.
+
+    Examples
+    ========
+
+    >>> from sympy.categories import Object, NamedMorphism, Diagram
+    >>> from sympy import pprint, default_sort_key
+    >>> A = Object("A")
+    >>> B = Object("B")
+    >>> C = Object("C")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> g = NamedMorphism(B, C, "g")
+    >>> d = Diagram([f, g])
+    >>> premises_keys = sorted(d.premises.keys(), key=default_sort_key)
+    >>> pprint(premises_keys, use_unicode=False)
+    [g*f:A-->C, id:A-->A, id:B-->B, id:C-->C, f:A-->B, g:B-->C]
+    >>> pprint(d.premises, use_unicode=False)
+    {g*f:A-->C: EmptySet, id:A-->A: EmptySet, id:B-->B: EmptySet,
+     id:C-->C: EmptySet, f:A-->B: EmptySet, g:B-->C: EmptySet}
+    >>> d = Diagram([f, g], {g * f: "unique"})
+    >>> pprint(d.conclusions,use_unicode=False)
+    {g*f:A-->C: {unique}}
+
+    References
+    ==========
+
+    [Pare1970] B. Pareigis: Categories and functors.  Academic Press, 1970.
+
+    """
+    @staticmethod
+    def _set_dict_union(dictionary, key, value):
+        """
+        If ``key`` is in ``dictionary``, set the new value of ``key``
+        to be the union between the old value and ``value``.
+        Otherwise, set the value of ``key`` to ``value.
+
+        Returns ``True`` if the key already was in the dictionary and
+        ``False`` otherwise.
+        """
+        if key in dictionary:
+            dictionary[key] = dictionary[key] | value
+            return True
+        else:
+            dictionary[key] = value
+            return False
+
+    @staticmethod
+    def _add_morphism_closure(morphisms, morphism, props, add_identities=True,
+                              recurse_composites=True):
+        """
+        Adds a morphism and its attributes to the supplied dictionary
+        ``morphisms``.  If ``add_identities`` is True, also adds the
+        identity morphisms for the domain and the codomain of
+        ``morphism``.
+        """
+        if not Diagram._set_dict_union(morphisms, morphism, props):
+            # We have just added a new morphism.
+
+            if isinstance(morphism, IdentityMorphism):
+                if props:
+                    # Properties for identity morphisms don't really
+                    # make sense, because very much is known about
+                    # identity morphisms already, so much that they
+                    # are trivial.  Having properties for identity
+                    # morphisms would only be confusing.
+                    raise ValueError(
+                        "Instances of IdentityMorphism cannot have properties.")
+                return
+
+            if add_identities:
+                empty = EmptySet
+
+                id_dom = IdentityMorphism(morphism.domain)
+                id_cod = IdentityMorphism(morphism.codomain)
+
+                Diagram._set_dict_union(morphisms, id_dom, empty)
+                Diagram._set_dict_union(morphisms, id_cod, empty)
+
+            for existing_morphism, existing_props in list(morphisms.items()):
+                new_props = existing_props & props
+                if morphism.domain == existing_morphism.codomain:
+                    left = morphism * existing_morphism
+                    Diagram._set_dict_union(morphisms, left, new_props)
+                if morphism.codomain == existing_morphism.domain:
+                    right = existing_morphism * morphism
+                    Diagram._set_dict_union(morphisms, right, new_props)
+
+            if isinstance(morphism, CompositeMorphism) and recurse_composites:
+                # This is a composite morphism, add its components as
+                # well.
+                empty = EmptySet
+                for component in morphism.components:
+                    Diagram._add_morphism_closure(morphisms, component, empty,
+                                                  add_identities)
+
+    def __new__(cls, *args):
+        """
+        Construct a new instance of Diagram.
+
+        Explanation
+        ===========
+
+        If no arguments are supplied, an empty diagram is created.
+
+        If at least an argument is supplied, ``args[0]`` is
+        interpreted as the premises of the diagram.  If ``args[0]`` is
+        a list, it is interpreted as a list of :class:`Morphism`'s, in
+        which each :class:`Morphism` has an empty set of properties.
+        If ``args[0]`` is a Python dictionary or a :class:`Dict`, it
+        is interpreted as a dictionary associating to some
+        :class:`Morphism`'s some properties.
+
+        If at least two arguments are supplied ``args[1]`` is
+        interpreted as the conclusions of the diagram.  The type of
+        ``args[1]`` is interpreted in exactly the same way as the type
+        of ``args[0]``.  If only one argument is supplied, the diagram
+        has no conclusions.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> from sympy.categories import IdentityMorphism, Diagram
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> d = Diagram([f, g])
+        >>> IdentityMorphism(A) in d.premises.keys()
+        True
+        >>> g * f in d.premises.keys()
+        True
+        >>> d = Diagram([f, g], {g * f: "unique"})
+        >>> d.conclusions[g * f]
+        {unique}
+
+        """
+        premises = {}
+        conclusions = {}
+
+        # Here we will keep track of the objects which appear in the
+        # premises.
+        objects = EmptySet
+
+        if len(args) >= 1:
+            # We've got some premises in the arguments.
+            premises_arg = args[0]
+
+            if isinstance(premises_arg, list):
+                # The user has supplied a list of morphisms, none of
+                # which have any attributes.
+                empty = EmptySet
+
+                for morphism in premises_arg:
+                    objects |= FiniteSet(morphism.domain, morphism.codomain)
+                    Diagram._add_morphism_closure(premises, morphism, empty)
+            elif isinstance(premises_arg, (dict, Dict)):
+                # The user has supplied a dictionary of morphisms and
+                # their properties.
+                for morphism, props in premises_arg.items():
+                    objects |= FiniteSet(morphism.domain, morphism.codomain)
+                    Diagram._add_morphism_closure(
+                        premises, morphism, FiniteSet(*props) if iterable(props) else FiniteSet(props))
+
+        if len(args) >= 2:
+            # We also have some conclusions.
+            conclusions_arg = args[1]
+
+            if isinstance(conclusions_arg, list):
+                # The user has supplied a list of morphisms, none of
+                # which have any attributes.
+                empty = EmptySet
+
+                for morphism in conclusions_arg:
+                    # Check that no new objects appear in conclusions.
+                    if ((sympify(objects.contains(morphism.domain)) is S.true) and
+                        (sympify(objects.contains(morphism.codomain)) is S.true)):
+                        # No need to add identities and recurse
+                        # composites this time.
+                        Diagram._add_morphism_closure(
+                            conclusions, morphism, empty, add_identities=False,
+                            recurse_composites=False)
+            elif isinstance(conclusions_arg, (dict, Dict)):
+                # The user has supplied a dictionary of morphisms and
+                # their properties.
+                for morphism, props in conclusions_arg.items():
+                    # Check that no new objects appear in conclusions.
+                    if (morphism.domain in objects) and \
+                       (morphism.codomain in objects):
+                        # No need to add identities and recurse
+                        # composites this time.
+                        Diagram._add_morphism_closure(
+                            conclusions, morphism, FiniteSet(*props) if iterable(props) else FiniteSet(props),
+                            add_identities=False, recurse_composites=False)
+
+        return Basic.__new__(cls, Dict(premises), Dict(conclusions), objects)
+
+    @property
+    def premises(self):
+        """
+        Returns the premises of this diagram.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> from sympy.categories import IdentityMorphism, Diagram
+        >>> from sympy import pretty
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> id_A = IdentityMorphism(A)
+        >>> id_B = IdentityMorphism(B)
+        >>> d = Diagram([f])
+        >>> print(pretty(d.premises, use_unicode=False))
+        {id:A-->A: EmptySet, id:B-->B: EmptySet, f:A-->B: EmptySet}
+
+        """
+        return self.args[0]
+
+    @property
+    def conclusions(self):
+        """
+        Returns the conclusions of this diagram.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> from sympy.categories import IdentityMorphism, Diagram
+        >>> from sympy import FiniteSet
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> d = Diagram([f, g])
+        >>> IdentityMorphism(A) in d.premises.keys()
+        True
+        >>> g * f in d.premises.keys()
+        True
+        >>> d = Diagram([f, g], {g * f: "unique"})
+        >>> d.conclusions[g * f] == FiniteSet("unique")
+        True
+
+        """
+        return self.args[1]
+
+    @property
+    def objects(self):
+        """
+        Returns the :class:`~.FiniteSet` of objects that appear in this
+        diagram.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism, Diagram
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> d = Diagram([f, g])
+        >>> d.objects
+        {Object("A"), Object("B"), Object("C")}
+
+        """
+        return self.args[2]
+
+    def hom(self, A, B):
+        """
+        Returns a 2-tuple of sets of morphisms between objects ``A`` and
+        ``B``: one set of morphisms listed as premises, and the other set
+        of morphisms listed as conclusions.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism, Diagram
+        >>> from sympy import pretty
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> d = Diagram([f, g], {g * f: "unique"})
+        >>> print(pretty(d.hom(A, C), use_unicode=False))
+        ({g*f:A-->C}, {g*f:A-->C})
+
+        See Also
+        ========
+        Object, Morphism
+        """
+        premises = EmptySet
+        conclusions = EmptySet
+
+        for morphism in self.premises.keys():
+            if (morphism.domain == A) and (morphism.codomain == B):
+                premises |= FiniteSet(morphism)
+        for morphism in self.conclusions.keys():
+            if (morphism.domain == A) and (morphism.codomain == B):
+                conclusions |= FiniteSet(morphism)
+
+        return (premises, conclusions)
+
+    def is_subdiagram(self, diagram):
+        """
+        Checks whether ``diagram`` is a subdiagram of ``self``.
+        Diagram `D'` is a subdiagram of `D` if all premises
+        (conclusions) of `D'` are contained in the premises
+        (conclusions) of `D`.  The morphisms contained
+        both in `D'` and `D` should have the same properties for `D'`
+        to be a subdiagram of `D`.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism, Diagram
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> d = Diagram([f, g], {g * f: "unique"})
+        >>> d1 = Diagram([f])
+        >>> d.is_subdiagram(d1)
+        True
+        >>> d1.is_subdiagram(d)
+        False
+        """
+        premises = all((m in self.premises) and
+                       (diagram.premises[m] == self.premises[m])
+                       for m in diagram.premises)
+        if not premises:
+            return False
+
+        conclusions = all((m in self.conclusions) and
+                          (diagram.conclusions[m] == self.conclusions[m])
+                          for m in diagram.conclusions)
+
+        # Premises is surely ``True`` here.
+        return conclusions
+
+    def subdiagram_from_objects(self, objects):
+        """
+        If ``objects`` is a subset of the objects of ``self``, returns
+        a diagram which has as premises all those premises of ``self``
+        which have a domains and codomains in ``objects``, likewise
+        for conclusions.  Properties are preserved.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism, Diagram
+        >>> from sympy import FiniteSet
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> d = Diagram([f, g], {f: "unique", g*f: "veryunique"})
+        >>> d1 = d.subdiagram_from_objects(FiniteSet(A, B))
+        >>> d1 == Diagram([f], {f: "unique"})
+        True
+        """
+        if not objects.is_subset(self.objects):
+            raise ValueError(
+                "Supplied objects should all belong to the diagram.")
+
+        new_premises = {}
+        for morphism, props in self.premises.items():
+            if ((sympify(objects.contains(morphism.domain)) is S.true) and
+                (sympify(objects.contains(morphism.codomain)) is S.true)):
+                new_premises[morphism] = props
+
+        new_conclusions = {}
+        for morphism, props in self.conclusions.items():
+            if ((sympify(objects.contains(morphism.domain)) is S.true) and
+                (sympify(objects.contains(morphism.codomain)) is S.true)):
+                new_conclusions[morphism] = props
+
+        return Diagram(new_premises, new_conclusions)

.venv/lib/python3.12/site-packages/sympy/categories/diagram_drawing.py

@@ -0,0 +1,2580 @@
+r"""
+This module contains the functionality to arrange the nodes of a
+diagram on an abstract grid, and then to produce a graphical
+representation of the grid.
+
+The currently supported back-ends are Xy-pic [Xypic].
+
+Layout Algorithm
+================
+
+This section provides an overview of the algorithms implemented in
+:class:`DiagramGrid` to lay out diagrams.
+
+The first step of the algorithm is the removal composite and identity
+morphisms which do not have properties in the supplied diagram.  The
+premises and conclusions of the diagram are then merged.
+
+The generic layout algorithm begins with the construction of the
+"skeleton" of the diagram.  The skeleton is an undirected graph which
+has the objects of the diagram as vertices and has an (undirected)
+edge between each pair of objects between which there exist morphisms.
+The direction of the morphisms does not matter at this stage.  The
+skeleton also includes an edge between each pair of vertices `A` and
+`C` such that there exists an object `B` which is connected via
+a morphism to `A`, and via a morphism to `C`.
+
+The skeleton constructed in this way has the property that every
+object is a vertex of a triangle formed by three edges of the
+skeleton.  This property lies at the base of the generic layout
+algorithm.
+
+After the skeleton has been constructed, the algorithm lists all
+triangles which can be formed.  Note that some triangles will not have
+all edges corresponding to morphisms which will actually be drawn.
+Triangles which have only one edge or less which will actually be
+drawn are immediately discarded.
+
+The list of triangles is sorted according to the number of edges which
+correspond to morphisms, then the triangle with the least number of such
+edges is selected.  One of such edges is picked and the corresponding
+objects are placed horizontally, on a grid.  This edge is recorded to
+be in the fringe.  The algorithm then finds a "welding" of a triangle
+to the fringe.  A welding is an edge in the fringe where a triangle
+could be attached.  If the algorithm succeeds in finding such a
+welding, it adds to the grid that vertex of the triangle which was not
+yet included in any edge in the fringe and records the two new edges in
+the fringe.  This process continues iteratively until all objects of
+the diagram has been placed or until no more weldings can be found.
+
+An edge is only removed from the fringe when a welding to this edge
+has been found, and there is no room around this edge to place
+another vertex.
+
+When no more weldings can be found, but there are still triangles
+left, the algorithm searches for a possibility of attaching one of the
+remaining triangles to the existing structure by a vertex.  If such a
+possibility is found, the corresponding edge of the found triangle is
+placed in the found space and the iterative process of welding
+triangles restarts.
+
+When logical groups are supplied, each of these groups is laid out
+independently.  Then a diagram is constructed in which groups are
+objects and any two logical groups between which there exist morphisms
+are connected via a morphism.  This diagram is laid out.  Finally,
+the grid which includes all objects of the initial diagram is
+constructed by replacing the cells which contain logical groups with
+the corresponding laid out grids, and by correspondingly expanding the
+rows and columns.
+
+The sequential layout algorithm begins by constructing the
+underlying undirected graph defined by the morphisms obtained after
+simplifying premises and conclusions and merging them (see above).
+The vertex with the minimal degree is then picked up and depth-first
+search is started from it.  All objects which are located at distance
+`n` from the root in the depth-first search tree, are positioned in
+the `n`-th column of the resulting grid.  The sequential layout will
+therefore attempt to lay the objects out along a line.
+
+References
+==========
+
+.. [Xypic] https://xy-pic.sourceforge.net/
+
+"""
+from sympy.categories import (CompositeMorphism, IdentityMorphism,
+                              NamedMorphism, Diagram)
+from sympy.core import Dict, Symbol, default_sort_key
+from sympy.printing.latex import latex
+from sympy.sets import FiniteSet
+from sympy.utilities.iterables import iterable
+from sympy.utilities.decorator import doctest_depends_on
+
+from itertools import chain
+
+
+__doctest_requires__ = {('preview_diagram',): 'pyglet'}
+
+
+class _GrowableGrid:
+    """
+    Holds a growable grid of objects.
+
+    Explanation
+    ===========
+
+    It is possible to append or prepend a row or a column to the grid
+    using the corresponding methods.  Prepending rows or columns has
+    the effect of changing the coordinates of the already existing
+    elements.
+
+    This class currently represents a naive implementation of the
+    functionality with little attempt at optimisation.
+    """
+    def __init__(self, width, height):
+        self._width = width
+        self._height = height
+
+        self._array = [[None for j in range(width)] for i in range(height)]
+
+    @property
+    def width(self):
+        return self._width
+
+    @property
+    def height(self):
+        return self._height
+
+    def __getitem__(self, i_j):
+        """
+        Returns the element located at in the i-th line and j-th
+        column.
+        """
+        i, j = i_j
+        return self._array[i][j]
+
+    def __setitem__(self, i_j, newvalue):
+        """
+        Sets the element located at in the i-th line and j-th
+        column.
+        """
+        i, j = i_j
+        self._array[i][j] = newvalue
+
+    def append_row(self):
+        """
+        Appends an empty row to the grid.
+        """
+        self._height += 1
+        self._array.append([None for j in range(self._width)])
+
+    def append_column(self):
+        """
+        Appends an empty column to the grid.
+        """
+        self._width += 1
+        for i in range(self._height):
+            self._array[i].append(None)
+
+    def prepend_row(self):
+        """
+        Prepends the grid with an empty row.
+        """
+        self._height += 1
+        self._array.insert(0, [None for j in range(self._width)])
+
+    def prepend_column(self):
+        """
+        Prepends the grid with an empty column.
+        """
+        self._width += 1
+        for i in range(self._height):
+            self._array[i].insert(0, None)
+
+
+class DiagramGrid:
+    r"""
+    Constructs and holds the fitting of the diagram into a grid.
+
+    Explanation
+    ===========
+
+    The mission of this class is to analyse the structure of the
+    supplied diagram and to place its objects on a grid such that,
+    when the objects and the morphisms are actually drawn, the diagram
+    would be "readable", in the sense that there will not be many
+    intersections of moprhisms.  This class does not perform any
+    actual drawing.  It does strive nevertheless to offer sufficient
+    metadata to draw a diagram.
+
+    Consider the following simple diagram.
+
+    >>> from sympy.categories import Object, NamedMorphism
+    >>> from sympy.categories import Diagram, DiagramGrid
+    >>> from sympy import pprint
+    >>> A = Object("A")
+    >>> B = Object("B")
+    >>> C = Object("C")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> g = NamedMorphism(B, C, "g")
+    >>> diagram = Diagram([f, g])
+
+    The simplest way to have a diagram laid out is the following:
+
+    >>> grid = DiagramGrid(diagram)
+    >>> (grid.width, grid.height)
+    (2, 2)
+    >>> pprint(grid)
+    A  B
+    <BLANKLINE>
+       C
+
+    Sometimes one sees the diagram as consisting of logical groups.
+    One can advise ``DiagramGrid`` as to such groups by employing the
+    ``groups`` keyword argument.
+
+    Consider the following diagram:
+
+    >>> D = Object("D")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> g = NamedMorphism(B, C, "g")
+    >>> h = NamedMorphism(D, A, "h")
+    >>> k = NamedMorphism(D, B, "k")
+    >>> diagram = Diagram([f, g, h, k])
+
+    Lay it out with generic layout:
+
+    >>> grid = DiagramGrid(diagram)
+    >>> pprint(grid)
+    A  B  D
+    <BLANKLINE>
+       C
+
+    Now, we can group the objects `A` and `D` to have them near one
+    another:
+
+    >>> grid = DiagramGrid(diagram, groups=[[A, D], B, C])
+    >>> pprint(grid)
+    B     C
+    <BLANKLINE>
+    A  D
+
+    Note how the positioning of the other objects changes.
+
+    Further indications can be supplied to the constructor of
+    :class:`DiagramGrid` using keyword arguments.  The currently
+    supported hints are explained in the following paragraphs.
+
+    :class:`DiagramGrid` does not automatically guess which layout
+    would suit the supplied diagram better.  Consider, for example,
+    the following linear diagram:
+
+    >>> E = Object("E")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> g = NamedMorphism(B, C, "g")
+    >>> h = NamedMorphism(C, D, "h")
+    >>> i = NamedMorphism(D, E, "i")
+    >>> diagram = Diagram([f, g, h, i])
+
+    When laid out with the generic layout, it does not get to look
+    linear:
+
+    >>> grid = DiagramGrid(diagram)
+    >>> pprint(grid)
+    A  B
+    <BLANKLINE>
+       C  D
+    <BLANKLINE>
+          E
+
+    To get it laid out in a line, use ``layout="sequential"``:
+
+    >>> grid = DiagramGrid(diagram, layout="sequential")
+    >>> pprint(grid)
+    A  B  C  D  E
+
+    One may sometimes need to transpose the resulting layout.  While
+    this can always be done by hand, :class:`DiagramGrid` provides a
+    hint for that purpose:
+
+    >>> grid = DiagramGrid(diagram, layout="sequential", transpose=True)
+    >>> pprint(grid)
+    A
+    <BLANKLINE>
+    B
+    <BLANKLINE>
+    C
+    <BLANKLINE>
+    D
+    <BLANKLINE>
+    E
+
+    Separate hints can also be provided for each group.  For an
+    example, refer to ``tests/test_drawing.py``, and see the different
+    ways in which the five lemma [FiveLemma] can be laid out.
+
+    See Also
+    ========
+
+    Diagram
+
+    References
+    ==========
+
+    .. [FiveLemma] https://en.wikipedia.org/wiki/Five_lemma
+    """
+    @staticmethod
+    def _simplify_morphisms(morphisms):
+        """
+        Given a dictionary mapping morphisms to their properties,
+        returns a new dictionary in which there are no morphisms which
+        do not have properties, and which are compositions of other
+        morphisms included in the dictionary.  Identities are dropped
+        as well.
+        """
+        newmorphisms = {}
+        for morphism, props in morphisms.items():
+            if isinstance(morphism, CompositeMorphism) and not props:
+                continue
+            elif isinstance(morphism, IdentityMorphism):
+                continue
+            else:
+                newmorphisms[morphism] = props
+        return newmorphisms
+
+    @staticmethod
+    def _merge_premises_conclusions(premises, conclusions):
+        """
+        Given two dictionaries of morphisms and their properties,
+        produces a single dictionary which includes elements from both
+        dictionaries.  If a morphism has some properties in premises
+        and also in conclusions, the properties in conclusions take
+        priority.
+        """
+        return dict(chain(premises.items(), conclusions.items()))
+
+    @staticmethod
+    def _juxtapose_edges(edge1, edge2):
+        """
+        If ``edge1`` and ``edge2`` have precisely one common endpoint,
+        returns an edge which would form a triangle with ``edge1`` and
+        ``edge2``.
+
+        If ``edge1`` and ``edge2`` do not have a common endpoint,
+        returns ``None``.
+
+        If ``edge1`` and ``edge`` are the same edge, returns ``None``.
+        """
+        intersection = edge1 & edge2
+        if len(intersection) != 1:
+            # The edges either have no common points or are equal.
+            return None
+
+        # The edges have a common endpoint.  Extract the different
+        # endpoints and set up the new edge.
+        return (edge1 - intersection) | (edge2 - intersection)
+
+    @staticmethod
+    def _add_edge_append(dictionary, edge, elem):
+        """
+        If ``edge`` is not in ``dictionary``, adds ``edge`` to the
+        dictionary and sets its value to ``[elem]``.  Otherwise
+        appends ``elem`` to the value of existing entry.
+
+        Note that edges are undirected, thus `(A, B) = (B, A)`.
+        """
+        if edge in dictionary:
+            dictionary[edge].append(elem)
+        else:
+            dictionary[edge] = [elem]
+
+    @staticmethod
+    def _build_skeleton(morphisms):
+        """
+        Creates a dictionary which maps edges to corresponding
+        morphisms.  Thus for a morphism `f:A\rightarrow B`, the edge
+        `(A, B)` will be associated with `f`.  This function also adds
+        to the list those edges which are formed by juxtaposition of
+        two edges already in the list.  These new edges are not
+        associated with any morphism and are only added to assure that
+        the diagram can be decomposed into triangles.
+        """
+        edges = {}
+        # Create edges for morphisms.
+        for morphism in morphisms:
+            DiagramGrid._add_edge_append(
+                edges, frozenset([morphism.domain, morphism.codomain]), morphism)
+
+        # Create new edges by juxtaposing existing edges.
+        edges1 = dict(edges)
+        for w in edges1:
+            for v in edges1:
+                wv = DiagramGrid._juxtapose_edges(w, v)
+                if wv and wv not in edges:
+                    edges[wv] = []
+
+        return edges
+
+    @staticmethod
+    def _list_triangles(edges):
+        """
+        Builds the set of triangles formed by the supplied edges.  The
+        triangles are arbitrary and need not be commutative.  A
+        triangle is a set that contains all three of its sides.
+        """
+        triangles = set()
+
+        for w in edges:
+            for v in edges:
+                wv = DiagramGrid._juxtapose_edges(w, v)
+                if wv and wv in edges:
+                    triangles.add(frozenset([w, v, wv]))
+
+        return triangles
+
+    @staticmethod
+    def _drop_redundant_triangles(triangles, skeleton):
+        """
+        Returns a list which contains only those triangles who have
+        morphisms associated with at least two edges.
+        """
+        return [tri for tri in triangles
+                if len([e for e in tri if skeleton[e]]) >= 2]
+
+    @staticmethod
+    def _morphism_length(morphism):
+        """
+        Returns the length of a morphism.  The length of a morphism is
+        the number of components it consists of.  A non-composite
+        morphism is of length 1.
+        """
+        if isinstance(morphism, CompositeMorphism):
+            return len(morphism.components)
+        else:
+            return 1
+
+    @staticmethod
+    def _compute_triangle_min_sizes(triangles, edges):
+        r"""
+        Returns a dictionary mapping triangles to their minimal sizes.
+        The minimal size of a triangle is the sum of maximal lengths
+        of morphisms associated to the sides of the triangle.  The
+        length of a morphism is the number of components it consists
+        of.  A non-composite morphism is of length 1.
+
+        Sorting triangles by this metric attempts to address two
+        aspects of layout.  For triangles with only simple morphisms
+        in the edge, this assures that triangles with all three edges
+        visible will get typeset after triangles with less visible
+        edges, which sometimes minimizes the necessity in diagonal
+        arrows.  For triangles with composite morphisms in the edges,
+        this assures that objects connected with shorter morphisms
+        will be laid out first, resulting the visual proximity of
+        those objects which are connected by shorter morphisms.
+        """
+        triangle_sizes = {}
+        for triangle in triangles:
+            size = 0
+            for e in triangle:
+                morphisms = edges[e]
+                if morphisms:
+                    size += max(DiagramGrid._morphism_length(m)
+                                for m in morphisms)
+            triangle_sizes[triangle] = size
+        return triangle_sizes
+
+    @staticmethod
+    def _triangle_objects(triangle):
+        """
+        Given a triangle, returns the objects included in it.
+        """
+        # A triangle is a frozenset of three two-element frozensets
+        # (the edges).  This chains the three edges together and
+        # creates a frozenset from the iterator, thus producing a
+        # frozenset of objects of the triangle.
+        return frozenset(chain(*tuple(triangle)))
+
+    @staticmethod
+    def _other_vertex(triangle, edge):
+        """
+        Given a triangle and an edge of it, returns the vertex which
+        opposes the edge.
+        """
+        # This gets the set of objects of the triangle and then
+        # subtracts the set of objects employed in ``edge`` to get the
+        # vertex opposite to ``edge``.
+        return list(DiagramGrid._triangle_objects(triangle) - set(edge))[0]
+
+    @staticmethod
+    def _empty_point(pt, grid):
+        """
+        Checks if the cell at coordinates ``pt`` is either empty or
+        out of the bounds of the grid.
+        """
+        if (pt[0] < 0) or (pt[1] < 0) or \
+           (pt[0] >= grid.height) or (pt[1] >= grid.width):
+            return True
+        return grid[pt] is None
+
+    @staticmethod
+    def _put_object(coords, obj, grid, fringe):
+        """
+        Places an object at the coordinate ``cords`` in ``grid``,
+        growing the grid and updating ``fringe``, if necessary.
+        Returns (0, 0) if no row or column has been prepended, (1, 0)
+        if a row was prepended, (0, 1) if a column was prepended and
+        (1, 1) if both a column and a row were prepended.
+        """
+        (i, j) = coords
+        offset = (0, 0)
+        if i == -1:
+            grid.prepend_row()
+            i = 0
+            offset = (1, 0)
+            for k in range(len(fringe)):
+                ((i1, j1), (i2, j2)) = fringe[k]
+                fringe[k] = ((i1 + 1, j1), (i2 + 1, j2))
+        elif i == grid.height:
+            grid.append_row()
+
+        if j == -1:
+            j = 0
+            offset = (offset[0], 1)
+            grid.prepend_column()
+            for k in range(len(fringe)):
+                ((i1, j1), (i2, j2)) = fringe[k]
+                fringe[k] = ((i1, j1 + 1), (i2, j2 + 1))
+        elif j == grid.width:
+            grid.append_column()
+
+        grid[i, j] = obj
+        return offset
+
+    @staticmethod
+    def _choose_target_cell(pt1, pt2, edge, obj, skeleton, grid):
+        """
+        Given two points, ``pt1`` and ``pt2``, and the welding edge
+        ``edge``, chooses one of the two points to place the opposing
+        vertex ``obj`` of the triangle.  If neither of this points
+        fits, returns ``None``.
+        """
+        pt1_empty = DiagramGrid._empty_point(pt1, grid)
+        pt2_empty = DiagramGrid._empty_point(pt2, grid)
+
+        if pt1_empty and pt2_empty:
+            # Both cells are empty.  Of these two, choose that cell
+            # which will assure that a visible edge of the triangle
+            # will be drawn perpendicularly to the current welding
+            # edge.
+
+            A = grid[edge[0]]
+
+            if skeleton.get(frozenset([A, obj])):
+                return pt1
+            else:
+                return pt2
+        if pt1_empty:
+            return pt1
+        elif pt2_empty:
+            return pt2
+        else:
+            return None
+
+    @staticmethod
+    def _find_triangle_to_weld(triangles, fringe, grid):
+        """
+        Finds, if possible, a triangle and an edge in the ``fringe`` to
+        which the triangle could be attached.  Returns the tuple
+        containing the triangle and the index of the corresponding
+        edge in the ``fringe``.
+
+        This function relies on the fact that objects are unique in
+        the diagram.
+        """
+        for triangle in triangles:
+            for (a, b) in fringe:
+                if frozenset([grid[a], grid[b]]) in triangle:
+                    return (triangle, (a, b))
+        return None
+
+    @staticmethod
+    def _weld_triangle(tri, welding_edge, fringe, grid, skeleton):
+        """
+        If possible, welds the triangle ``tri`` to ``fringe`` and
+        returns ``False``.  If this method encounters a degenerate
+        situation in the fringe and corrects it such that a restart of
+        the search is required, it returns ``True`` (which means that
+        a restart in finding triangle weldings is required).
+
+        A degenerate situation is a situation when an edge listed in
+        the fringe does not belong to the visual boundary of the
+        diagram.
+        """
+        a, b = welding_edge
+        target_cell = None
+
+        obj = DiagramGrid._other_vertex(tri, (grid[a], grid[b]))
+
+        # We now have a triangle and an edge where it can be welded to
+        # the fringe.  Decide where to place the other vertex of the
+        # triangle and check for degenerate situations en route.
+
+        if (abs(a[0] - b[0]) == 1) and (abs(a[1] - b[1]) == 1):
+            # A diagonal edge.
+            target_cell = (a[0], b[1])
+            if grid[target_cell]:
+                # That cell is already occupied.
+                target_cell = (b[0], a[1])
+
+                if grid[target_cell]:
+                    # Degenerate situation, this edge is not
+                    # on the actual fringe.  Correct the
+                    # fringe and go on.
+                    fringe.remove((a, b))
+                    return True
+        elif a[0] == b[0]:
+            # A horizontal edge.  We first attempt to build the
+            # triangle in the downward direction.
+
+            down_left = a[0] + 1, a[1]
+            down_right = a[0] + 1, b[1]
+
+            target_cell = DiagramGrid._choose_target_cell(
+                down_left, down_right, (a, b), obj, skeleton, grid)
+
+            if not target_cell:
+                # No room below this edge.  Check above.
+                up_left = a[0] - 1, a[1]
+                up_right = a[0] - 1, b[1]
+
+                target_cell = DiagramGrid._choose_target_cell(
+                    up_left, up_right, (a, b), obj, skeleton, grid)
+
+                if not target_cell:
+                    # This edge is not in the fringe, remove it
+                    # and restart.
+                    fringe.remove((a, b))
+                    return True
+        elif a[1] == b[1]:
+            # A vertical edge.  We will attempt to place the other
+            # vertex of the triangle to the right of this edge.
+            right_up = a[0], a[1] + 1
+            right_down = b[0], a[1] + 1
+
+            target_cell = DiagramGrid._choose_target_cell(
+                right_up, right_down, (a, b), obj, skeleton, grid)
+
+            if not target_cell:
+                # No room to the left.  See what's to the right.
+                left_up = a[0], a[1] - 1
+                left_down = b[0], a[1] - 1
+
+                target_cell = DiagramGrid._choose_target_cell(
+                    left_up, left_down, (a, b), obj, skeleton, grid)
+
+                if not target_cell:
+                    # This edge is not in the fringe, remove it
+                    # and restart.
+                    fringe.remove((a, b))
+                    return True
+
+        # We now know where to place the other vertex of the
+        # triangle.
+        offset = DiagramGrid._put_object(target_cell, obj, grid, fringe)
+
+        # Take care of the displacement of coordinates if a row or
+        # a column was prepended.
+        target_cell = (target_cell[0] + offset[0],
+                       target_cell[1] + offset[1])
+        a = (a[0] + offset[0], a[1] + offset[1])
+        b = (b[0] + offset[0], b[1] + offset[1])
+
+        fringe.extend([(a, target_cell), (b, target_cell)])
+
+        # No restart is required.
+        return False
+
+    @staticmethod
+    def _triangle_key(tri, triangle_sizes):
+        """
+        Returns a key for the supplied triangle.  It should be the
+        same independently of the hash randomisation.
+        """
+        objects = sorted(
+            DiagramGrid._triangle_objects(tri), key=default_sort_key)
+        return (triangle_sizes[tri], default_sort_key(objects))
+
+    @staticmethod
+    def _pick_root_edge(tri, skeleton):
+        """
+        For a given triangle always picks the same root edge.  The
+        root edge is the edge that will be placed first on the grid.
+        """
+        candidates = [sorted(e, key=default_sort_key)
+                      for e in tri if skeleton[e]]
+        sorted_candidates = sorted(candidates, key=default_sort_key)
+        # Don't forget to assure the proper ordering of the vertices
+        # in this edge.
+        return tuple(sorted(sorted_candidates[0], key=default_sort_key))
+
+    @staticmethod
+    def _drop_irrelevant_triangles(triangles, placed_objects):
+        """
+        Returns only those triangles whose set of objects is not
+        completely included in ``placed_objects``.
+        """
+        return [tri for tri in triangles if not placed_objects.issuperset(
+            DiagramGrid._triangle_objects(tri))]
+
+    @staticmethod
+    def _grow_pseudopod(triangles, fringe, grid, skeleton, placed_objects):
+        """
+        Starting from an object in the existing structure on the ``grid``,
+        adds an edge to which a triangle from ``triangles`` could be
+        welded.  If this method has found a way to do so, it returns
+        the object it has just added.
+
+        This method should be applied when ``_weld_triangle`` cannot
+        find weldings any more.
+        """
+        for i in range(grid.height):
+            for j in range(grid.width):
+                obj = grid[i, j]
+                if not obj:
+                    continue
+
+                # Here we need to choose a triangle which has only
+                # ``obj`` in common with the existing structure.  The
+                # situations when this is not possible should be
+                # handled elsewhere.
+
+                def good_triangle(tri):
+                    objs = DiagramGrid._triangle_objects(tri)
+                    return obj in objs and \
+                        placed_objects & (objs - {obj}) == set()
+
+                tris = [tri for tri in triangles if good_triangle(tri)]
+                if not tris:
+                    # This object is not interesting.
+                    continue
+
+                # Pick the "simplest" of the triangles which could be
+                # attached.  Remember that the list of triangles is
+                # sorted according to their "simplicity" (see
+                # _compute_triangle_min_sizes for the metric).
+                #
+                # Note that ``tris`` are sequentially built from
+                # ``triangles``, so we don't have to worry about hash
+                # randomisation.
+                tri = tris[0]
+
+                # We have found a triangle which could be attached to
+                # the existing structure by a vertex.
+
+                candidates = sorted([e for e in tri if skeleton[e]],
+                                    key=lambda e: FiniteSet(*e).sort_key())
+                edges = [e for e in candidates if obj in e]
+
+                # Note that a meaningful edge (i.e., and edge that is
+                # associated with a morphism) containing ``obj``
+                # always exists.  That's because all triangles are
+                # guaranteed to have at least two meaningful edges.
+                # See _drop_redundant_triangles.
+
+                # Get the object at the other end of the edge.
+                edge = edges[0]
+                other_obj = tuple(edge - frozenset([obj]))[0]
+
+                # Now check for free directions.  When checking for
+                # free directions, prefer the horizontal and vertical
+                # directions.
+                neighbours = [(i - 1, j), (i, j + 1), (i + 1, j), (i, j - 1),
+                              (i - 1, j - 1), (i - 1, j + 1), (i + 1, j - 1), (i + 1, j + 1)]
+
+                for pt in neighbours:
+                    if DiagramGrid._empty_point(pt, grid):
+                        # We have a found a place to grow the
+                        # pseudopod into.
+                        offset = DiagramGrid._put_object(
+                            pt, other_obj, grid, fringe)
+
+                        i += offset[0]
+                        j += offset[1]
+                        pt = (pt[0] + offset[0], pt[1] + offset[1])
+                        fringe.append(((i, j), pt))
+
+                        return other_obj
+
+        # This diagram is actually cooler that I can handle.  Fail cowardly.
+        return None
+
+    @staticmethod
+    def _handle_groups(diagram, groups, merged_morphisms, hints):
+        """
+        Given the slightly preprocessed morphisms of the diagram,
+        produces a grid laid out according to ``groups``.
+
+        If a group has hints, it is laid out with those hints only,
+        without any influence from ``hints``.  Otherwise, it is laid
+        out with ``hints``.
+        """
+        def lay_out_group(group, local_hints):
+            """
+            If ``group`` is a set of objects, uses a ``DiagramGrid``
+            to lay it out and returns the grid.  Otherwise returns the
+            object (i.e., ``group``).  If ``local_hints`` is not
+            empty, it is supplied to ``DiagramGrid`` as the dictionary
+            of hints.  Otherwise, the ``hints`` argument of
+            ``_handle_groups`` is used.
+            """
+            if isinstance(group, FiniteSet):
+                # Set up the corresponding object-to-group
+                # mappings.
+                for obj in group:
+                    obj_groups[obj] = group
+
+                # Lay out the current group.
+                if local_hints:
+                    groups_grids[group] = DiagramGrid(
+                        diagram.subdiagram_from_objects(group), **local_hints)
+                else:
+                    groups_grids[group] = DiagramGrid(
+                        diagram.subdiagram_from_objects(group), **hints)
+            else:
+                obj_groups[group] = group
+
+        def group_to_finiteset(group):
+            """
+            Converts ``group`` to a :class:``FiniteSet`` if it is an
+            iterable.
+            """
+            if iterable(group):
+                return FiniteSet(*group)
+            else:
+                return group
+
+        obj_groups = {}
+        groups_grids = {}
+
+        # We would like to support various containers to represent
+        # groups.  To achieve that, before laying each group out, it
+        # should be converted to a FiniteSet, because that is what the
+        # following code expects.
+
+        if isinstance(groups, (dict, Dict)):
+            finiteset_groups = {}
+            for group, local_hints in groups.items():
+                finiteset_group = group_to_finiteset(group)
+                finiteset_groups[finiteset_group] = local_hints
+                lay_out_group(group, local_hints)
+            groups = finiteset_groups
+        else:
+            finiteset_groups = []
+            for group in groups:
+                finiteset_group = group_to_finiteset(group)
+                finiteset_groups.append(finiteset_group)
+                lay_out_group(finiteset_group, None)
+            groups = finiteset_groups
+
+        new_morphisms = []
+        for morphism in merged_morphisms:
+            dom = obj_groups[morphism.domain]
+            cod = obj_groups[morphism.codomain]
+            # Note that we are not really interested in morphisms
+            # which do not employ two different groups, because
+            # these do not influence the layout.
+            if dom != cod:
+                # These are essentially unnamed morphisms; they are
+                # not going to mess in the final layout.  By giving
+                # them the same names, we avoid unnecessary
+                # duplicates.
+                new_morphisms.append(NamedMorphism(dom, cod, "dummy"))
+
+        # Lay out the new diagram.  Since these are dummy morphisms,
+        # properties and conclusions are irrelevant.
+        top_grid = DiagramGrid(Diagram(new_morphisms))
+
+        # We now have to substitute the groups with the corresponding
+        # grids, laid out at the beginning of this function.  Compute
+        # the size of each row and column in the grid, so that all
+        # nested grids fit.
+
+        def group_size(group):
+            """
+            For the supplied group (or object, eventually), returns
+            the size of the cell that will hold this group (object).
+            """
+            if group in groups_grids:
+                grid = groups_grids[group]
+                return (grid.height, grid.width)
+            else:
+                return (1, 1)
+
+        row_heights = [max(group_size(top_grid[i, j])[0]
+                           for j in range(top_grid.width))
+                       for i in range(top_grid.height)]
+
+        column_widths = [max(group_size(top_grid[i, j])[1]
+                             for i in range(top_grid.height))
+                         for j in range(top_grid.width)]
+
+        grid = _GrowableGrid(sum(column_widths), sum(row_heights))
+
+        real_row = 0
+        real_column = 0
+        for logical_row in range(top_grid.height):
+            for logical_column in range(top_grid.width):
+                obj = top_grid[logical_row, logical_column]
+
+                if obj in groups_grids:
+                    # This is a group.  Copy the corresponding grid in
+                    # place.
+                    local_grid = groups_grids[obj]
+                    for i in range(local_grid.height):
+                        for j in range(local_grid.width):
+                            grid[real_row + i,
+                                real_column + j] = local_grid[i, j]
+                else:
+                    # This is an object.  Just put it there.
+                    grid[real_row, real_column] = obj
+
+                real_column += column_widths[logical_column]
+            real_column = 0
+            real_row += row_heights[logical_row]
+
+        return grid
+
+    @staticmethod
+    def _generic_layout(diagram, merged_morphisms):
+        """
+        Produces the generic layout for the supplied diagram.
+        """
+        all_objects = set(diagram.objects)
+        if len(all_objects) == 1:
+            # There only one object in the diagram, just put in on 1x1
+            # grid.
+            grid = _GrowableGrid(1, 1)
+            grid[0, 0] = tuple(all_objects)[0]
+            return grid
+
+        skeleton = DiagramGrid._build_skeleton(merged_morphisms)
+
+        grid = _GrowableGrid(2, 1)
+
+        if len(skeleton) == 1:
+            # This diagram contains only one morphism.  Draw it
+            # horizontally.
+            objects = sorted(all_objects, key=default_sort_key)
+            grid[0, 0] = objects[0]
+            grid[0, 1] = objects[1]
+
+            return grid
+
+        triangles = DiagramGrid._list_triangles(skeleton)
+        triangles = DiagramGrid._drop_redundant_triangles(triangles, skeleton)
+        triangle_sizes = DiagramGrid._compute_triangle_min_sizes(
+            triangles, skeleton)
+
+        triangles = sorted(triangles, key=lambda tri:
+                           DiagramGrid._triangle_key(tri, triangle_sizes))
+
+        # Place the first edge on the grid.
+        root_edge = DiagramGrid._pick_root_edge(triangles[0], skeleton)
+        grid[0, 0], grid[0, 1] = root_edge
+        fringe = [((0, 0), (0, 1))]
+
+        # Record which objects we now have on the grid.
+        placed_objects = set(root_edge)
+
+        while placed_objects != all_objects:
+            welding = DiagramGrid._find_triangle_to_weld(
+                triangles, fringe, grid)
+
+            if welding:
+                (triangle, welding_edge) = welding
+
+                restart_required = DiagramGrid._weld_triangle(
+                    triangle, welding_edge, fringe, grid, skeleton)
+                if restart_required:
+                    continue
+
+                placed_objects.update(
+                    DiagramGrid._triangle_objects(triangle))
+            else:
+                # No more weldings found.  Try to attach triangles by
+                # vertices.
+                new_obj = DiagramGrid._grow_pseudopod(
+                    triangles, fringe, grid, skeleton, placed_objects)
+
+                if not new_obj:
+                    # No more triangles can be attached, not even by
+                    # the edge.  We will set up a new diagram out of
+                    # what has been left, laid it out independently,
+                    # and then attach it to this one.
+
+                    remaining_objects = all_objects - placed_objects
+
+                    remaining_diagram = diagram.subdiagram_from_objects(
+                        FiniteSet(*remaining_objects))
+                    remaining_grid = DiagramGrid(remaining_diagram)
+
+                    # Now, let's glue ``remaining_grid`` to ``grid``.
+                    final_width = grid.width + remaining_grid.width
+                    final_height = max(grid.height, remaining_grid.height)
+                    final_grid = _GrowableGrid(final_width, final_height)
+
+                    for i in range(grid.width):
+                        for j in range(grid.height):
+                            final_grid[i, j] = grid[i, j]
+
+                    start_j = grid.width
+                    for i in range(remaining_grid.height):
+                        for j in range(remaining_grid.width):
+                            final_grid[i, start_j + j] = remaining_grid[i, j]
+
+                    return final_grid
+
+                placed_objects.add(new_obj)
+
+            triangles = DiagramGrid._drop_irrelevant_triangles(
+                triangles, placed_objects)
+
+        return grid
+
+    @staticmethod
+    def _get_undirected_graph(objects, merged_morphisms):
+        """
+        Given the objects and the relevant morphisms of a diagram,
+        returns the adjacency lists of the underlying undirected
+        graph.
+        """
+        adjlists = {obj: [] for obj in objects}
+
+        for morphism in merged_morphisms:
+            adjlists[morphism.domain].append(morphism.codomain)
+            adjlists[morphism.codomain].append(morphism.domain)
+
+        # Assure that the objects in the adjacency list are always in
+        # the same order.
+        for obj in adjlists.keys():
+            adjlists[obj].sort(key=default_sort_key)
+
+        return adjlists
+
+    @staticmethod
+    def _sequential_layout(diagram, merged_morphisms):
+        r"""
+        Lays out the diagram in "sequential" layout.  This method
+        will attempt to produce a result as close to a line as
+        possible.  For linear diagrams, the result will actually be a
+        line.
+        """
+        objects = diagram.objects
+        sorted_objects = sorted(objects, key=default_sort_key)
+
+        # Set up the adjacency lists of the underlying undirected
+        # graph of ``merged_morphisms``.
+        adjlists = DiagramGrid._get_undirected_graph(objects, merged_morphisms)
+
+        root = min(sorted_objects, key=lambda x: len(adjlists[x]))
+        grid = _GrowableGrid(1, 1)
+        grid[0, 0] = root
+
+        placed_objects = {root}
+
+        def place_objects(pt, placed_objects):
+            """
+            Does depth-first search in the underlying graph of the
+            diagram and places the objects en route.
+            """
+            # We will start placing new objects from here.
+            new_pt = (pt[0], pt[1] + 1)
+
+            for adjacent_obj in adjlists[grid[pt]]:
+                if adjacent_obj in placed_objects:
+                    # This object has already been placed.
+                    continue
+
+                DiagramGrid._put_object(new_pt, adjacent_obj, grid, [])
+                placed_objects.add(adjacent_obj)
+                placed_objects.update(place_objects(new_pt, placed_objects))
+
+                new_pt = (new_pt[0] + 1, new_pt[1])
+
+            return placed_objects
+
+        place_objects((0, 0), placed_objects)
+
+        return grid
+
+    @staticmethod
+    def _drop_inessential_morphisms(merged_morphisms):
+        r"""
+        Removes those morphisms which should appear in the diagram,
+        but which have no relevance to object layout.
+
+        Currently this removes "loop" morphisms: the non-identity
+        morphisms with the same domains and codomains.
+        """
+        morphisms = [m for m in merged_morphisms if m.domain != m.codomain]
+        return morphisms
+
+    @staticmethod
+    def _get_connected_components(objects, merged_morphisms):
+        """
+        Given a container of morphisms, returns a list of connected
+        components formed by these morphisms.  A connected component
+        is represented by a diagram consisting of the corresponding
+        morphisms.
+        """
+        component_index = {}
+        for o in objects:
+            component_index[o] = None
+
+        # Get the underlying undirected graph of the diagram.
+        adjlist = DiagramGrid._get_undirected_graph(objects, merged_morphisms)
+
+        def traverse_component(object, current_index):
+            """
+            Does a depth-first search traversal of the component
+            containing ``object``.
+            """
+            component_index[object] = current_index
+            for o in adjlist[object]:
+                if component_index[o] is None:
+                    traverse_component(o, current_index)
+
+        # Traverse all components.
+        current_index = 0
+        for o in adjlist:
+            if component_index[o] is None:
+                traverse_component(o, current_index)
+                current_index += 1
+
+        # List the objects of the components.
+        component_objects = [[] for i in range(current_index)]
+        for o, idx in component_index.items():
+            component_objects[idx].append(o)
+
+        # Finally, list the morphisms belonging to each component.
+        #
+        # Note: If some objects are isolated, they will not get any
+        # morphisms at this stage, and since the layout algorithm
+        # relies, we are essentially going to lose this object.
+        # Therefore, check if there are isolated objects and, for each
+        # of them, provide the trivial identity morphism.  It will get
+        # discarded later, but the object will be there.
+
+        component_morphisms = []
+        for component in component_objects:
+            current_morphisms = {}
+            for m in merged_morphisms:
+                if (m.domain in component) and (m.codomain in component):
+                    current_morphisms[m] = merged_morphisms[m]
+
+            if len(component) == 1:
+                # Let's add an identity morphism, for the sake of
+                # surely having morphisms in this component.
+                current_morphisms[IdentityMorphism(component[0])] = FiniteSet()
+
+            component_morphisms.append(Diagram(current_morphisms))
+
+        return component_morphisms
+
+    def __init__(self, diagram, groups=None, **hints):
+        premises = DiagramGrid._simplify_morphisms(diagram.premises)
+        conclusions = DiagramGrid._simplify_morphisms(diagram.conclusions)
+        all_merged_morphisms = DiagramGrid._merge_premises_conclusions(
+            premises, conclusions)
+        merged_morphisms = DiagramGrid._drop_inessential_morphisms(
+            all_merged_morphisms)
+
+        # Store the merged morphisms for later use.
+        self._morphisms = all_merged_morphisms
+
+        components = DiagramGrid._get_connected_components(
+            diagram.objects, all_merged_morphisms)
+
+        if groups and (groups != diagram.objects):
+            # Lay out the diagram according to the groups.
+            self._grid = DiagramGrid._handle_groups(
+                diagram, groups, merged_morphisms, hints)
+        elif len(components) > 1:
+            # Note that we check for connectedness _before_ checking
+            # the layout hints because the layout strategies don't
+            # know how to deal with disconnected diagrams.
+
+            # The diagram is disconnected.  Lay out the components
+            # independently.
+            grids = []
+
+            # Sort the components to eventually get the grids arranged
+            # in a fixed, hash-independent order.
+            components = sorted(components, key=default_sort_key)
+
+            for component in components:
+                grid = DiagramGrid(component, **hints)
+                grids.append(grid)
+
+            # Throw the grids together, in a line.
+            total_width = sum(g.width for g in grids)
+            total_height = max(g.height for g in grids)
+
+            grid = _GrowableGrid(total_width, total_height)
+            start_j = 0
+            for g in grids:
+                for i in range(g.height):
+                    for j in range(g.width):
+                        grid[i, start_j + j] = g[i, j]
+
+                start_j += g.width
+
+            self._grid = grid
+        elif "layout" in hints:
+            if hints["layout"] == "sequential":
+                self._grid = DiagramGrid._sequential_layout(
+                    diagram, merged_morphisms)
+        else:
+            self._grid = DiagramGrid._generic_layout(diagram, merged_morphisms)
+
+        if hints.get("transpose"):
+            # Transpose the resulting grid.
+            grid = _GrowableGrid(self._grid.height, self._grid.width)
+            for i in range(self._grid.height):
+                for j in range(self._grid.width):
+                    grid[j, i] = self._grid[i, j]
+            self._grid = grid
+
+    @property
+    def width(self):
+        """
+        Returns the number of columns in this diagram layout.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> from sympy.categories import Diagram, DiagramGrid
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> diagram = Diagram([f, g])
+        >>> grid = DiagramGrid(diagram)
+        >>> grid.width
+        2
+
+        """
+        return self._grid.width
+
+    @property
+    def height(self):
+        """
+        Returns the number of rows in this diagram layout.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> from sympy.categories import Diagram, DiagramGrid
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> diagram = Diagram([f, g])
+        >>> grid = DiagramGrid(diagram)
+        >>> grid.height
+        2
+
+        """
+        return self._grid.height
+
+    def __getitem__(self, i_j):
+        """
+        Returns the object placed in the row ``i`` and column ``j``.
+        The indices are 0-based.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> from sympy.categories import Diagram, DiagramGrid
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> diagram = Diagram([f, g])
+        >>> grid = DiagramGrid(diagram)
+        >>> (grid[0, 0], grid[0, 1])
+        (Object("A"), Object("B"))
+        >>> (grid[1, 0], grid[1, 1])
+        (None, Object("C"))
+
+        """
+        i, j = i_j
+        return self._grid[i, j]
+
+    @property
+    def morphisms(self):
+        """
+        Returns those morphisms (and their properties) which are
+        sufficiently meaningful to be drawn.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> from sympy.categories import Diagram, DiagramGrid
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> diagram = Diagram([f, g])
+        >>> grid = DiagramGrid(diagram)
+        >>> grid.morphisms
+        {NamedMorphism(Object("A"), Object("B"), "f"): EmptySet,
+        NamedMorphism(Object("B"), Object("C"), "g"): EmptySet}
+
+        """
+        return self._morphisms
+
+    def __str__(self):
+        """
+        Produces a string representation of this class.
+
+        This method returns a string representation of the underlying
+        list of lists of objects.
+
+        Examples
+        ========
+
+        >>> from sympy.categories import Object, NamedMorphism
+        >>> from sympy.categories import Diagram, DiagramGrid
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> diagram = Diagram([f, g])
+        >>> grid = DiagramGrid(diagram)
+        >>> print(grid)
+        [[Object("A"), Object("B")],
+        [None, Object("C")]]
+
+        """
+        return repr(self._grid._array)
+
+
+class ArrowStringDescription:
+    r"""
+    Stores the information necessary for producing an Xy-pic
+    description of an arrow.
+
+    The principal goal of this class is to abstract away the string
+    representation of an arrow and to also provide the functionality
+    to produce the actual Xy-pic string.
+
+    ``unit`` sets the unit which will be used to specify the amount of
+    curving and other distances.  ``horizontal_direction`` should be a
+    string of ``"r"`` or ``"l"`` specifying the horizontal offset of the
+    target cell of the arrow relatively to the current one.
+    ``vertical_direction`` should  specify the vertical offset using a
+    series of either ``"d"`` or ``"u"``.  ``label_position`` should be
+    either ``"^"``, ``"_"``,  or ``"|"`` to specify that the label should
+    be positioned above the arrow, below the arrow or just over the arrow,
+    in a break.  Note that the notions "above" and "below" are relative
+    to arrow direction.  ``label`` stores the morphism label.
+
+    This works as follows (disregard the yet unexplained arguments):
+
+    >>> from sympy.categories.diagram_drawing import ArrowStringDescription
+    >>> astr = ArrowStringDescription(
+    ... unit="mm", curving=None, curving_amount=None,
+    ... looping_start=None, looping_end=None, horizontal_direction="d",
+    ... vertical_direction="r", label_position="_", label="f")
+    >>> print(str(astr))
+    \ar[dr]_{f}
+
+    ``curving`` should be one of ``"^"``, ``"_"`` to specify in which
+    direction the arrow is going to curve. ``curving_amount`` is a number
+    describing how many ``unit``'s the morphism is going to curve:
+
+    >>> astr = ArrowStringDescription(
+    ... unit="mm", curving="^", curving_amount=12,
+    ... looping_start=None, looping_end=None, horizontal_direction="d",
+    ... vertical_direction="r", label_position="_", label="f")
+    >>> print(str(astr))
+    \ar@/^12mm/[dr]_{f}
+
+    ``looping_start`` and ``looping_end`` are currently only used for
+    loop morphisms, those which have the same domain and codomain.
+    These two attributes should store a valid Xy-pic direction and
+    specify, correspondingly, the direction the arrow gets out into
+    and the direction the arrow gets back from:
+
+    >>> astr = ArrowStringDescription(
+    ... unit="mm", curving=None, curving_amount=None,
+    ... looping_start="u", looping_end="l", horizontal_direction="",
+    ... vertical_direction="", label_position="_", label="f")
+    >>> print(str(astr))
+    \ar@(u,l)[]_{f}
+
+    ``label_displacement`` controls how far the arrow label is from
+    the ends of the arrow.  For example, to position the arrow label
+    near the arrow head, use ">":
+
+    >>> astr = ArrowStringDescription(
+    ... unit="mm", curving="^", curving_amount=12,
+    ... looping_start=None, looping_end=None, horizontal_direction="d",
+    ... vertical_direction="r", label_position="_", label="f")
+    >>> astr.label_displacement = ">"
+    >>> print(str(astr))
+    \ar@/^12mm/[dr]_>{f}
+
+    Finally, ``arrow_style`` is used to specify the arrow style.  To
+    get a dashed arrow, for example, use "{-->}" as arrow style:
+
+    >>> astr = ArrowStringDescription(
+    ... unit="mm", curving="^", curving_amount=12,
+    ... looping_start=None, looping_end=None, horizontal_direction="d",
+    ... vertical_direction="r", label_position="_", label="f")
+    >>> astr.arrow_style = "{-->}"
+    >>> print(str(astr))
+    \ar@/^12mm/@{-->}[dr]_{f}
+
+    Notes
+    =====
+
+    Instances of :class:`ArrowStringDescription` will be constructed
+    by :class:`XypicDiagramDrawer` and provided for further use in
+    formatters.  The user is not expected to construct instances of
+    :class:`ArrowStringDescription` themselves.
+
+    To be able to properly utilise this class, the reader is encouraged
+    to checkout the Xy-pic user guide, available at [Xypic].
+
+    See Also
+    ========
+
+    XypicDiagramDrawer
+
+    References
+    ==========
+
+    .. [Xypic] https://xy-pic.sourceforge.net/
+    """
+    def __init__(self, unit, curving, curving_amount, looping_start,
+                 looping_end, horizontal_direction, vertical_direction,
+                 label_position, label):
+        self.unit = unit
+        self.curving = curving
+        self.curving_amount = curving_amount
+        self.looping_start = looping_start
+        self.looping_end = looping_end
+        self.horizontal_direction = horizontal_direction
+        self.vertical_direction = vertical_direction
+        self.label_position = label_position
+        self.label = label
+
+        self.label_displacement = ""
+        self.arrow_style = ""
+
+        # This flag shows that the position of the label of this
+        # morphism was set while typesetting a curved morphism and
+        # should not be modified later.
+        self.forced_label_position = False
+
+    def __str__(self):
+        if self.curving:
+            curving_str = "@/%s%d%s/" % (self.curving, self.curving_amount,
+                                         self.unit)
+        else:
+            curving_str = ""
+
+        if self.looping_start and self.looping_end:
+            looping_str = "@(%s,%s)" % (self.looping_start, self.looping_end)
+        else:
+            looping_str = ""
+
+        if self.arrow_style:
+
+            style_str = "@" + self.arrow_style
+        else:
+            style_str = ""
+
+        return "\\ar%s%s%s[%s%s]%s%s{%s}" % \
+               (curving_str, looping_str, style_str, self.horizontal_direction,
+                self.vertical_direction, self.label_position,
+                self.label_displacement, self.label)
+
+
+class XypicDiagramDrawer:
+    r"""
+    Given a :class:`~.Diagram` and the corresponding
+    :class:`DiagramGrid`, produces the Xy-pic representation of the
+    diagram.
+
+    The most important method in this class is ``draw``.  Consider the
+    following triangle diagram:
+
+    >>> from sympy.categories import Object, NamedMorphism, Diagram
+    >>> from sympy.categories import DiagramGrid, XypicDiagramDrawer
+    >>> A = Object("A")
+    >>> B = Object("B")
+    >>> C = Object("C")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> g = NamedMorphism(B, C, "g")
+    >>> diagram = Diagram([f, g], {g * f: "unique"})
+
+    To draw this diagram, its objects need to be laid out with a
+    :class:`DiagramGrid`::
+
+    >>> grid = DiagramGrid(diagram)
+
+    Finally, the drawing:
+
+    >>> drawer = XypicDiagramDrawer()
+    >>> print(drawer.draw(diagram, grid))
+    \xymatrix{
+    A \ar[d]_{g\circ f} \ar[r]^{f} & B \ar[ld]^{g} \\
+    C &
+    }
+
+    For further details see the docstring of this method.
+
+    To control the appearance of the arrows, formatters are used.  The
+    dictionary ``arrow_formatters`` maps morphisms to formatter
+    functions.  A formatter is accepts an
+    :class:`ArrowStringDescription` and is allowed to modify any of
+    the arrow properties exposed thereby.  For example, to have all
+    morphisms with the property ``unique`` appear as dashed arrows,
+    and to have their names prepended with `\exists !`, the following
+    should be done:
+
+    >>> def formatter(astr):
+    ...   astr.label = r"\exists !" + astr.label
+    ...   astr.arrow_style = "{-->}"
+    >>> drawer.arrow_formatters["unique"] = formatter
+    >>> print(drawer.draw(diagram, grid))
+    \xymatrix{
+    A \ar@{-->}[d]_{\exists !g\circ f} \ar[r]^{f} & B \ar[ld]^{g} \\
+    C &
+    }
+
+    To modify the appearance of all arrows in the diagram, set
+    ``default_arrow_formatter``.  For example, to place all morphism
+    labels a little bit farther from the arrow head so that they look
+    more centred, do as follows:
+
+    >>> def default_formatter(astr):
+    ...   astr.label_displacement = "(0.45)"
+    >>> drawer.default_arrow_formatter = default_formatter
+    >>> print(drawer.draw(diagram, grid))
+    \xymatrix{
+    A \ar@{-->}[d]_(0.45){\exists !g\circ f} \ar[r]^(0.45){f} & B \ar[ld]^(0.45){g} \\
+    C &
+    }
+
+    In some diagrams some morphisms are drawn as curved arrows.
+    Consider the following diagram:
+
+    >>> D = Object("D")
+    >>> E = Object("E")
+    >>> h = NamedMorphism(D, A, "h")
+    >>> k = NamedMorphism(D, B, "k")
+    >>> diagram = Diagram([f, g, h, k])
+    >>> grid = DiagramGrid(diagram)
+    >>> drawer = XypicDiagramDrawer()
+    >>> print(drawer.draw(diagram, grid))
+    \xymatrix{
+    A \ar[r]_{f} & B \ar[d]^{g} & D \ar[l]^{k} \ar@/_3mm/[ll]_{h} \\
+    & C &
+    }
+
+    To control how far the morphisms are curved by default, one can
+    use the ``unit`` and ``default_curving_amount`` attributes:
+
+    >>> drawer.unit = "cm"
+    >>> drawer.default_curving_amount = 1
+    >>> print(drawer.draw(diagram, grid))
+    \xymatrix{
+    A \ar[r]_{f} & B \ar[d]^{g} & D \ar[l]^{k} \ar@/_1cm/[ll]_{h} \\
+    & C &
+    }
+
+    In some diagrams, there are multiple curved morphisms between the
+    same two objects.  To control by how much the curving changes
+    between two such successive morphisms, use
+    ``default_curving_step``:
+
+    >>> drawer.default_curving_step = 1
+    >>> h1 = NamedMorphism(A, D, "h1")
+    >>> diagram = Diagram([f, g, h, k, h1])
+    >>> grid = DiagramGrid(diagram)
+    >>> print(drawer.draw(diagram, grid))
+    \xymatrix{
+    A \ar[r]_{f} \ar@/^1cm/[rr]^{h_{1}} & B \ar[d]^{g} & D \ar[l]^{k} \ar@/_2cm/[ll]_{h} \\
+    & C &
+    }
+
+    The default value of ``default_curving_step`` is 4 units.
+
+    See Also
+    ========
+
+    draw, ArrowStringDescription
+    """
+    def __init__(self):
+        self.unit = "mm"
+        self.default_curving_amount = 3
+        self.default_curving_step = 4
+
+        # This dictionary maps properties to the corresponding arrow
+        # formatters.
+        self.arrow_formatters = {}
+
+        # This is the default arrow formatter which will be applied to
+        # each arrow independently of its properties.
+        self.default_arrow_formatter = None
+
+    @staticmethod
+    def _process_loop_morphism(i, j, grid, morphisms_str_info, object_coords):
+        """
+        Produces the information required for constructing the string
+        representation of a loop morphism.  This function is invoked
+        from ``_process_morphism``.
+
+        See Also
+        ========
+
+        _process_morphism
+        """
+        curving = ""
+        label_pos = "^"
+        looping_start = ""
+        looping_end = ""
+
+        # This is a loop morphism.  Count how many morphisms stick
+        # in each of the four quadrants.  Note that straight
+        # vertical and horizontal morphisms count in two quadrants
+        # at the same time (i.e., a morphism going up counts both
+        # in the first and the second quadrants).
+
+        # The usual numbering (counterclockwise) of quadrants
+        # applies.
+        quadrant = [0, 0, 0, 0]
+
+        obj = grid[i, j]
+
+        for m, m_str_info in morphisms_str_info.items():
+            if (m.domain == obj) and (m.codomain == obj):
+                # That's another loop morphism.  Check how it
+                # loops and mark the corresponding quadrants as
+                # busy.
+                (l_s, l_e) = (m_str_info.looping_start, m_str_info.looping_end)
+
+                if (l_s, l_e) == ("r", "u"):
+                    quadrant[0] += 1
+                elif (l_s, l_e) == ("u", "l"):
+                    quadrant[1] += 1
+                elif (l_s, l_e) == ("l", "d"):
+                    quadrant[2] += 1
+                elif (l_s, l_e) == ("d", "r"):
+                    quadrant[3] += 1
+
+                continue
+            if m.domain == obj:
+                (end_i, end_j) = object_coords[m.codomain]
+                goes_out = True
+            elif m.codomain == obj:
+                (end_i, end_j) = object_coords[m.domain]
+                goes_out = False
+            else:
+                continue
+
+            d_i = end_i - i
+            d_j = end_j - j
+            m_curving = m_str_info.curving
+
+            if (d_i != 0) and (d_j != 0):
+                # This is really a diagonal morphism.  Detect the
+                # quadrant.
+                if (d_i > 0) and (d_j > 0):
+                    quadrant[0] += 1
+                elif (d_i > 0) and (d_j < 0):
+                    quadrant[1] += 1
+                elif (d_i < 0) and (d_j < 0):
+                    quadrant[2] += 1
+                elif (d_i < 0) and (d_j > 0):
+                    quadrant[3] += 1
+            elif d_i == 0:
+                # Knowing where the other end of the morphism is
+                # and which way it goes, we now have to decide
+                # which quadrant is now the upper one and which is
+                # the lower one.
+                if d_j > 0:
+                    if goes_out:
+                        upper_quadrant = 0
+                        lower_quadrant = 3
+                    else:
+                        upper_quadrant = 3
+                        lower_quadrant = 0
+                else:
+                    if goes_out:
+                        upper_quadrant = 2
+                        lower_quadrant = 1
+                    else:
+                        upper_quadrant = 1
+                        lower_quadrant = 2
+
+                if m_curving:
+                    if m_curving == "^":
+                        quadrant[upper_quadrant] += 1
+                    elif m_curving == "_":
+                        quadrant[lower_quadrant] += 1
+                else:
+                    # This morphism counts in both upper and lower
+                    # quadrants.
+                    quadrant[upper_quadrant] += 1
+                    quadrant[lower_quadrant] += 1
+            elif d_j == 0:
+                # Knowing where the other end of the morphism is
+                # and which way it goes, we now have to decide
+                # which quadrant is now the left one and which is
+                # the right one.
+                if d_i < 0:
+                    if goes_out:
+                        left_quadrant = 1
+                        right_quadrant = 0
+                    else:
+                        left_quadrant = 0
+                        right_quadrant = 1
+                else:
+                    if goes_out:
+                        left_quadrant = 3
+                        right_quadrant = 2
+                    else:
+                        left_quadrant = 2
+                        right_quadrant = 3
+
+                if m_curving:
+                    if m_curving == "^":
+                        quadrant[left_quadrant] += 1
+                    elif m_curving == "_":
+                        quadrant[right_quadrant] += 1
+                else:
+                    # This morphism counts in both upper and lower
+                    # quadrants.
+                    quadrant[left_quadrant] += 1
+                    quadrant[right_quadrant] += 1
+
+        # Pick the freest quadrant to curve our morphism into.
+        freest_quadrant = 0
+        for i in range(4):
+            if quadrant[i] < quadrant[freest_quadrant]:
+                freest_quadrant = i
+
+        # Now set up proper looping.
+        (looping_start, looping_end) = [("r", "u"), ("u", "l"), ("l", "d"),
+                                        ("d", "r")][freest_quadrant]
+
+        return (curving, label_pos, looping_start, looping_end)
+
+    @staticmethod
+    def _process_horizontal_morphism(i, j, target_j, grid, morphisms_str_info,
+                                     object_coords):
+        """
+        Produces the information required for constructing the string
+        representation of a horizontal morphism.  This function is
+        invoked from ``_process_morphism``.
+
+        See Also
+        ========
+
+        _process_morphism
+        """
+        # The arrow is horizontal.  Check if it goes from left to
+        # right (``backwards == False``) or from right to left
+        # (``backwards == True``).
+        backwards = False
+        start = j
+        end = target_j
+        if end < start:
+            (start, end) = (end, start)
+            backwards = True
+
+        # Let's see which objects are there between ``start`` and
+        # ``end``, and then count how many morphisms stick out
+        # upwards, and how many stick out downwards.
+        #
+        # For example, consider the situation:
+        #
+        #    B1 C1
+        #    |  |
+        # A--B--C--D
+        #    |
+        #    B2
+        #
+        # Between the objects `A` and `D` there are two objects:
+        # `B` and `C`.  Further, there are two morphisms which
+        # stick out upward (the ones between `B1` and `B` and
+        # between `C` and `C1`) and one morphism which sticks out
+        # downward (the one between `B and `B2`).
+        #
+        # We need this information to decide how to curve the
+        # arrow between `A` and `D`.  First of all, since there
+        # are two objects between `A` and `D``, we must curve the
+        # arrow.  Then, we will have it curve downward, because
+        # there is more space (less morphisms stick out downward
+        # than upward).
+        up = []
+        down = []
+        straight_horizontal = []
+        for k in range(start + 1, end):
+            obj = grid[i, k]
+            if not obj:
+                continue
+
+            for m in morphisms_str_info:
+                if m.domain == obj:
+                    (end_i, end_j) = object_coords[m.codomain]
+                elif m.codomain == obj:
+                    (end_i, end_j) = object_coords[m.domain]
+                else:
+                    continue
+
+                if end_i > i:
+                    down.append(m)
+                elif end_i < i:
+                    up.append(m)
+                elif not morphisms_str_info[m].curving:
+                    # This is a straight horizontal morphism,
+                    # because it has no curving.
+                    straight_horizontal.append(m)
+
+        if len(up) < len(down):
+            # More morphisms stick out downward than upward, let's
+            # curve the morphism up.
+            if backwards:
+                curving = "_"
+                label_pos = "_"
+            else:
+                curving = "^"
+                label_pos = "^"
+
+            # Assure that the straight horizontal morphisms have
+            # their labels on the lower side of the arrow.
+            for m in straight_horizontal:
+                (i1, j1) = object_coords[m.domain]
+                (i2, j2) = object_coords[m.codomain]
+
+                m_str_info = morphisms_str_info[m]
+                if j1 < j2:
+                    m_str_info.label_position = "_"
+                else:
+                    m_str_info.label_position = "^"
+
+                # Don't allow any further modifications of the
+                # position of this label.
+                m_str_info.forced_label_position = True
+        else:
+            # More morphisms stick out downward than upward, let's
+            # curve the morphism up.
+            if backwards:
+                curving = "^"
+                label_pos = "^"
+            else:
+                curving = "_"
+                label_pos = "_"
+
+            # Assure that the straight horizontal morphisms have
+            # their labels on the upper side of the arrow.
+            for m in straight_horizontal:
+                (i1, j1) = object_coords[m.domain]
+                (i2, j2) = object_coords[m.codomain]
+
+                m_str_info = morphisms_str_info[m]
+                if j1 < j2:
+                    m_str_info.label_position = "^"
+                else:
+                    m_str_info.label_position = "_"
+
+                # Don't allow any further modifications of the
+                # position of this label.
+                m_str_info.forced_label_position = True
+
+        return (curving, label_pos)
+
+    @staticmethod
+    def _process_vertical_morphism(i, j, target_i, grid, morphisms_str_info,
+                                   object_coords):
+        """
+        Produces the information required for constructing the string
+        representation of a vertical morphism.  This function is
+        invoked from ``_process_morphism``.
+
+        See Also
+        ========
+
+        _process_morphism
+        """
+        # This arrow is vertical.  Check if it goes from top to
+        # bottom (``backwards == False``) or from bottom to top
+        # (``backwards == True``).
+        backwards = False
+        start = i
+        end = target_i
+        if end < start:
+            (start, end) = (end, start)
+            backwards = True
+
+        # Let's see which objects are there between ``start`` and
+        # ``end``, and then count how many morphisms stick out to
+        # the left, and how many stick out to the right.
+        #
+        # See the corresponding comment in the previous branch of
+        # this if-statement for more details.
+        left = []
+        right = []
+        straight_vertical = []
+        for k in range(start + 1, end):
+            obj = grid[k, j]
+            if not obj:
+                continue
+
+            for m in morphisms_str_info:
+                if m.domain == obj:
+                    (end_i, end_j) = object_coords[m.codomain]
+                elif m.codomain == obj:
+                    (end_i, end_j) = object_coords[m.domain]
+                else:
+                    continue
+
+                if end_j > j:
+                    right.append(m)
+                elif end_j < j:
+                    left.append(m)
+                elif not morphisms_str_info[m].curving:
+                    # This is a straight vertical morphism,
+                    # because it has no curving.
+                    straight_vertical.append(m)
+
+        if len(left) < len(right):
+            # More morphisms stick out to the left than to the
+            # right, let's curve the morphism to the right.
+            if backwards:
+                curving = "^"
+                label_pos = "^"
+            else:
+                curving = "_"
+                label_pos = "_"
+
+            # Assure that the straight vertical morphisms have
+            # their labels on the left side of the arrow.
+            for m in straight_vertical:
+                (i1, j1) = object_coords[m.domain]
+                (i2, j2) = object_coords[m.codomain]
+
+                m_str_info = morphisms_str_info[m]
+                if i1 < i2:
+                    m_str_info.label_position = "^"
+                else:
+                    m_str_info.label_position = "_"
+
+                # Don't allow any further modifications of the
+                # position of this label.
+                m_str_info.forced_label_position = True
+        else:
+            # More morphisms stick out to the right than to the
+            # left, let's curve the morphism to the left.
+            if backwards:
+                curving = "_"
+                label_pos = "_"
+            else:
+                curving = "^"
+                label_pos = "^"
+
+            # Assure that the straight vertical morphisms have
+            # their labels on the right side of the arrow.
+            for m in straight_vertical:
+                (i1, j1) = object_coords[m.domain]
+                (i2, j2) = object_coords[m.codomain]
+
+                m_str_info = morphisms_str_info[m]
+                if i1 < i2:
+                    m_str_info.label_position = "_"
+                else:
+                    m_str_info.label_position = "^"
+
+                # Don't allow any further modifications of the
+                # position of this label.
+                m_str_info.forced_label_position = True
+
+        return (curving, label_pos)
+
+    def _process_morphism(self, diagram, grid, morphism, object_coords,
+                          morphisms, morphisms_str_info):
+        """
+        Given the required information, produces the string
+        representation of ``morphism``.
+        """
+        def repeat_string_cond(times, str_gt, str_lt):
+            """
+            If ``times > 0``, repeats ``str_gt`` ``times`` times.
+            Otherwise, repeats ``str_lt`` ``-times`` times.
+            """
+            if times > 0:
+                return str_gt * times
+            else:
+                return str_lt * (-times)
+
+        def count_morphisms_undirected(A, B):
+            """
+            Counts how many processed morphisms there are between the
+            two supplied objects.
+            """
+            return len([m for m in morphisms_str_info
+                        if {m.domain, m.codomain} == {A, B}])
+
+        def count_morphisms_filtered(dom, cod, curving):
+            """
+            Counts the processed morphisms which go out of ``dom``
+            into ``cod`` with curving ``curving``.
+            """
+            return len([m for m, m_str_info in morphisms_str_info.items()
+                        if (m.domain, m.codomain) == (dom, cod) and
+                        (m_str_info.curving == curving)])
+
+        (i, j) = object_coords[morphism.domain]
+        (target_i, target_j) = object_coords[morphism.codomain]
+
+        # We now need to determine the direction of
+        # the arrow.
+        delta_i = target_i - i
+        delta_j = target_j - j
+        vertical_direction = repeat_string_cond(delta_i,
+                                                "d", "u")
+        horizontal_direction = repeat_string_cond(delta_j,
+                                                  "r", "l")
+
+        curving = ""
+        label_pos = "^"
+        looping_start = ""
+        looping_end = ""
+
+        if (delta_i == 0) and (delta_j == 0):
+            # This is a loop morphism.
+            (curving, label_pos, looping_start,
+             looping_end) = XypicDiagramDrawer._process_loop_morphism(
+                 i, j, grid, morphisms_str_info, object_coords)
+        elif (delta_i == 0) and (abs(j - target_j) > 1):
+            # This is a horizontal morphism.
+            (curving, label_pos) = XypicDiagramDrawer._process_horizontal_morphism(
+                i, j, target_j, grid, morphisms_str_info, object_coords)
+        elif (delta_j == 0) and (abs(i - target_i) > 1):
+            # This is a vertical morphism.
+            (curving, label_pos) = XypicDiagramDrawer._process_vertical_morphism(
+                i, j, target_i, grid, morphisms_str_info, object_coords)
+
+        count = count_morphisms_undirected(morphism.domain, morphism.codomain)
+        curving_amount = ""
+        if curving:
+            # This morphisms should be curved anyway.
+            curving_amount = self.default_curving_amount + count * \
+                self.default_curving_step
+        elif count:
+            # There are no objects between the domain and codomain of
+            # the current morphism, but this is not there already are
+            # some morphisms with the same domain and codomain, so we
+            # have to curve this one.
+            curving = "^"
+            filtered_morphisms = count_morphisms_filtered(
+                morphism.domain, morphism.codomain, curving)
+            curving_amount = self.default_curving_amount + \
+                filtered_morphisms * \
+                self.default_curving_step
+
+        # Let's now get the name of the morphism.
+        morphism_name = ""
+        if isinstance(morphism, IdentityMorphism):
+            morphism_name = "id_{%s}" + latex(grid[i, j])
+        elif isinstance(morphism, CompositeMorphism):
+            component_names = [latex(Symbol(component.name)) for
+                               component in morphism.components]
+            component_names.reverse()
+            morphism_name = "\\circ ".join(component_names)
+        elif isinstance(morphism, NamedMorphism):
+            morphism_name = latex(Symbol(morphism.name))
+
+        return ArrowStringDescription(
+            self.unit, curving, curving_amount, looping_start,
+            looping_end, horizontal_direction, vertical_direction,
+            label_pos, morphism_name)
+
+    @staticmethod
+    def _check_free_space_horizontal(dom_i, dom_j, cod_j, grid):
+        """
+        For a horizontal morphism, checks whether there is free space
+        (i.e., space not occupied by any objects) above the morphism
+        or below it.
+        """
+        if dom_j < cod_j:
+            (start, end) = (dom_j, cod_j)
+            backwards = False
+        else:
+            (start, end) = (cod_j, dom_j)
+            backwards = True
+
+        # Check for free space above.
+        if dom_i == 0:
+            free_up = True
+        else:
+            free_up = all(grid[dom_i - 1, j] for j in
+                          range(start, end + 1))
+
+        # Check for free space below.
+        if dom_i == grid.height - 1:
+            free_down = True
+        else:
+            free_down = not any(grid[dom_i + 1, j] for j in
+                                range(start, end + 1))
+
+        return (free_up, free_down, backwards)
+
+    @staticmethod
+    def _check_free_space_vertical(dom_i, cod_i, dom_j, grid):
+        """
+        For a vertical morphism, checks whether there is free space
+        (i.e., space not occupied by any objects) to the left of the
+        morphism or to the right of it.
+        """
+        if dom_i < cod_i:
+            (start, end) = (dom_i, cod_i)
+            backwards = False
+        else:
+            (start, end) = (cod_i, dom_i)
+            backwards = True
+
+        # Check if there's space to the left.
+        if dom_j == 0:
+            free_left = True
+        else:
+            free_left = not any(grid[i, dom_j - 1] for i in
+                                range(start, end + 1))
+
+        if dom_j == grid.width - 1:
+            free_right = True
+        else:
+            free_right = not any(grid[i, dom_j + 1] for i in
+                                 range(start, end + 1))
+
+        return (free_left, free_right, backwards)
+
+    @staticmethod
+    def _check_free_space_diagonal(dom_i, cod_i, dom_j, cod_j, grid):
+        """
+        For a diagonal morphism, checks whether there is free space
+        (i.e., space not occupied by any objects) above the morphism
+        or below it.
+        """
+        def abs_xrange(start, end):
+            if start < end:
+                return range(start, end + 1)
+            else:
+                return range(end, start + 1)
+
+        if dom_i < cod_i and dom_j < cod_j:
+            # This morphism goes from top-left to
+            # bottom-right.
+            (start_i, start_j) = (dom_i, dom_j)
+            (end_i, end_j) = (cod_i, cod_j)
+            backwards = False
+        elif dom_i > cod_i and dom_j > cod_j:
+            # This morphism goes from bottom-right to
+            # top-left.
+            (start_i, start_j) = (cod_i, cod_j)
+            (end_i, end_j) = (dom_i, dom_j)
+            backwards = True
+        if dom_i < cod_i and dom_j > cod_j:
+            # This morphism goes from top-right to
+            # bottom-left.
+            (start_i, start_j) = (dom_i, dom_j)
+            (end_i, end_j) = (cod_i, cod_j)
+            backwards = True
+        elif dom_i > cod_i and dom_j < cod_j:
+            # This morphism goes from bottom-left to
+            # top-right.
+            (start_i, start_j) = (cod_i, cod_j)
+            (end_i, end_j) = (dom_i, dom_j)
+            backwards = False
+
+        # This is an attempt at a fast and furious strategy to
+        # decide where there is free space on the two sides of
+        # a diagonal morphism.  For a diagonal morphism
+        # starting at ``(start_i, start_j)`` and ending at
+        # ``(end_i, end_j)`` the rectangle defined by these
+        # two points is considered.  The slope of the diagonal
+        # ``alpha`` is then computed.  Then, for every cell
+        # ``(i, j)`` within the rectangle, the slope
+        # ``alpha1`` of the line through ``(start_i,
+        # start_j)`` and ``(i, j)`` is considered.  If
+        # ``alpha1`` is between 0 and ``alpha``, the point
+        # ``(i, j)`` is above the diagonal, if ``alpha1`` is
+        # between ``alpha`` and infinity, the point is below
+        # the diagonal.  Also note that, with some beforehand
+        # precautions, this trick works for both the main and
+        # the secondary diagonals of the rectangle.
+
+        # I have considered the possibility to only follow the
+        # shorter diagonals immediately above and below the
+        # main (or secondary) diagonal.  This, however,
+        # wouldn't have resulted in much performance gain or
+        # better detection of outer edges, because of
+        # relatively small sizes of diagram grids, while the
+        # code would have become harder to understand.
+
+        alpha = float(end_i - start_i)/(end_j - start_j)
+        free_up = True
+        free_down = True
+        for i in abs_xrange(start_i, end_i):
+            if not free_up and not free_down:
+                break
+
+            for j in abs_xrange(start_j, end_j):
+                if not free_up and not free_down:
+                    break
+
+                if (i, j) == (start_i, start_j):
+                    continue
+
+                if j == start_j:
+                    alpha1 = "inf"
+                else:
+                    alpha1 = float(i - start_i)/(j - start_j)
+
+                if grid[i, j]:
+                    if (alpha1 == "inf") or (abs(alpha1) > abs(alpha)):
+                        free_down = False
+                    elif abs(alpha1) < abs(alpha):
+                        free_up = False
+
+        return (free_up, free_down, backwards)
+
+    def _push_labels_out(self, morphisms_str_info, grid, object_coords):
+        """
+        For all straight morphisms which form the visual boundary of
+        the laid out diagram, puts their labels on their outer sides.
+        """
+        def set_label_position(free1, free2, pos1, pos2, backwards, m_str_info):
+            """
+            Given the information about room available to one side and
+            to the other side of a morphism (``free1`` and ``free2``),
+            sets the position of the morphism label in such a way that
+            it is on the freer side.  This latter operations involves
+            choice between ``pos1`` and ``pos2``, taking ``backwards``
+            in consideration.
+
+            Thus this function will do nothing if either both ``free1
+            == True`` and ``free2 == True`` or both ``free1 == False``
+            and ``free2 == False``.  In either case, choosing one side
+            over the other presents no advantage.
+            """
+            if backwards:
+                (pos1, pos2) = (pos2, pos1)
+
+            if free1 and not free2:
+                m_str_info.label_position = pos1
+            elif free2 and not free1:
+                m_str_info.label_position = pos2
+
+        for m, m_str_info in morphisms_str_info.items():
+            if m_str_info.curving or m_str_info.forced_label_position:
+                # This is either a curved morphism, and curved
+                # morphisms have other magic, or the position of this
+                # label has already been fixed.
+                continue
+
+            if m.domain == m.codomain:
+                # This is a loop morphism, their labels, again have a
+                # different magic.
+                continue
+
+            (dom_i, dom_j) = object_coords[m.domain]
+            (cod_i, cod_j) = object_coords[m.codomain]
+
+            if dom_i == cod_i:
+                # Horizontal morphism.
+                (free_up, free_down,
+                 backwards) = XypicDiagramDrawer._check_free_space_horizontal(
+                     dom_i, dom_j, cod_j, grid)
+
+                set_label_position(free_up, free_down, "^", "_",
+                                   backwards, m_str_info)
+            elif dom_j == cod_j:
+                # Vertical morphism.
+                (free_left, free_right,
+                 backwards) = XypicDiagramDrawer._check_free_space_vertical(
+                     dom_i, cod_i, dom_j, grid)
+
+                set_label_position(free_left, free_right, "_", "^",
+                                   backwards, m_str_info)
+            else:
+                # A diagonal morphism.
+                (free_up, free_down,
+                 backwards) = XypicDiagramDrawer._check_free_space_diagonal(
+                     dom_i, cod_i, dom_j, cod_j, grid)
+
+                set_label_position(free_up, free_down, "^", "_",
+                                   backwards, m_str_info)
+
+    @staticmethod
+    def _morphism_sort_key(morphism, object_coords):
+        """
+        Provides a morphism sorting key such that horizontal or
+        vertical morphisms between neighbouring objects come
+        first, then horizontal or vertical morphisms between more
+        far away objects, and finally, all other morphisms.
+        """
+        (i, j) = object_coords[morphism.domain]
+        (target_i, target_j) = object_coords[morphism.codomain]
+
+        if morphism.domain == morphism.codomain:
+            # Loop morphisms should get after diagonal morphisms
+            # so that the proper direction in which to curve the
+            # loop can be determined.
+            return (3, 0, default_sort_key(morphism))
+
+        if target_i == i:
+            return (1, abs(target_j - j), default_sort_key(morphism))
+
+        if target_j == j:
+            return (1, abs(target_i - i), default_sort_key(morphism))
+
+        # Diagonal morphism.
+        return (2, 0, default_sort_key(morphism))
+
+    @staticmethod
+    def _build_xypic_string(diagram, grid, morphisms,
+                            morphisms_str_info, diagram_format):
+        """
+        Given a collection of :class:`ArrowStringDescription`
+        describing the morphisms of a diagram and the object layout
+        information of a diagram, produces the final Xy-pic picture.
+        """
+        # Build the mapping between objects and morphisms which have
+        # them as domains.
+        object_morphisms = {}
+        for obj in diagram.objects:
+            object_morphisms[obj] = []
+        for morphism in morphisms:
+            object_morphisms[morphism.domain].append(morphism)
+
+        result = "\\xymatrix%s{\n" % diagram_format
+
+        for i in range(grid.height):
+            for j in range(grid.width):
+                obj = grid[i, j]
+                if obj:
+                    result += latex(obj) + " "
+
+                    morphisms_to_draw = object_morphisms[obj]
+                    for morphism in morphisms_to_draw:
+                        result += str(morphisms_str_info[morphism]) + " "
+
+                # Don't put the & after the last column.
+                if j < grid.width - 1:
+                    result += "& "
+
+            # Don't put the line break after the last row.
+            if i < grid.height - 1:
+                result += "\\\\"
+            result += "\n"
+
+        result += "}\n"
+
+        return result
+
+    def draw(self, diagram, grid, masked=None, diagram_format=""):
+        r"""
+        Returns the Xy-pic representation of ``diagram`` laid out in
+        ``grid``.
+
+        Consider the following simple triangle diagram.
+
+        >>> from sympy.categories import Object, NamedMorphism, Diagram
+        >>> from sympy.categories import DiagramGrid, XypicDiagramDrawer
+        >>> A = Object("A")
+        >>> B = Object("B")
+        >>> C = Object("C")
+        >>> f = NamedMorphism(A, B, "f")
+        >>> g = NamedMorphism(B, C, "g")
+        >>> diagram = Diagram([f, g], {g * f: "unique"})
+
+        To draw this diagram, its objects need to be laid out with a
+        :class:`DiagramGrid`::
+
+        >>> grid = DiagramGrid(diagram)
+
+        Finally, the drawing:
+
+        >>> drawer = XypicDiagramDrawer()
+        >>> print(drawer.draw(diagram, grid))
+        \xymatrix{
+        A \ar[d]_{g\circ f} \ar[r]^{f} & B \ar[ld]^{g} \\
+        C &
+        }
+
+        The argument ``masked`` can be used to skip morphisms in the
+        presentation of the diagram:
+
+        >>> print(drawer.draw(diagram, grid, masked=[g * f]))
+        \xymatrix{
+        A \ar[r]^{f} & B \ar[ld]^{g} \\
+        C &
+        }
+
+        Finally, the ``diagram_format`` argument can be used to
+        specify the format string of the diagram.  For example, to
+        increase the spacing by 1 cm, proceeding as follows:
+
+        >>> print(drawer.draw(diagram, grid, diagram_format="@+1cm"))
+        \xymatrix@+1cm{
+        A \ar[d]_{g\circ f} \ar[r]^{f} & B \ar[ld]^{g} \\
+        C &
+        }
+
+        """
+        # This method works in several steps.  It starts by removing
+        # the masked morphisms, if necessary, and then maps objects to
+        # their positions in the grid (coordinate tuples).  Remember
+        # that objects are unique in ``Diagram`` and in the layout
+        # produced by ``DiagramGrid``, so every object is mapped to a
+        # single coordinate pair.
+        #
+        # The next step is the central step and is concerned with
+        # analysing the morphisms of the diagram and deciding how to
+        # draw them.  For example, how to curve the arrows is decided
+        # at this step.  The bulk of the analysis is implemented in
+        # ``_process_morphism``, to the result of which the
+        # appropriate formatters are applied.
+        #
+        # The result of the previous step is a list of
+        # ``ArrowStringDescription``.  After the analysis and
+        # application of formatters, some extra logic tries to assure
+        # better positioning of morphism labels (for example, an
+        # attempt is made to avoid the situations when arrows cross
+        # labels).  This functionality constitutes the next step and
+        # is implemented in ``_push_labels_out``.  Note that label
+        # positions which have been set via a formatter are not
+        # affected in this step.
+        #
+        # Finally, at the closing step, the array of
+        # ``ArrowStringDescription`` and the layout information
+        # incorporated in ``DiagramGrid`` are combined to produce the
+        # resulting Xy-pic picture.  This part of code lies in
+        # ``_build_xypic_string``.
+
+        if not masked:
+            morphisms_props = grid.morphisms
+        else:
+            morphisms_props = {}
+            for m, props in grid.morphisms.items():
+                if m in masked:
+                    continue
+                morphisms_props[m] = props
+
+        # Build the mapping between objects and their position in the
+        # grid.
+        object_coords = {}
+        for i in range(grid.height):
+            for j in range(grid.width):
+                if grid[i, j]:
+                    object_coords[grid[i, j]] = (i, j)
+
+        morphisms = sorted(morphisms_props,
+                           key=lambda m: XypicDiagramDrawer._morphism_sort_key(
+                               m, object_coords))
+
+        # Build the tuples defining the string representations of
+        # morphisms.
+        morphisms_str_info = {}
+        for morphism in morphisms:
+            string_description = self._process_morphism(
+                diagram, grid, morphism, object_coords, morphisms,
+                morphisms_str_info)
+
+            if self.default_arrow_formatter:
+                self.default_arrow_formatter(string_description)
+
+            for prop in morphisms_props[morphism]:
+                # prop is a Symbol.  TODO: Find out why.
+                if prop.name in self.arrow_formatters:
+                    formatter = self.arrow_formatters[prop.name]
+                    formatter(string_description)
+
+            morphisms_str_info[morphism] = string_description
+
+        # Reposition the labels a bit.
+        self._push_labels_out(morphisms_str_info, grid, object_coords)
+
+        return XypicDiagramDrawer._build_xypic_string(
+            diagram, grid, morphisms, morphisms_str_info, diagram_format)
+
+
+def xypic_draw_diagram(diagram, masked=None, diagram_format="",
+                       groups=None, **hints):
+    r"""
+    Provides a shortcut combining :class:`DiagramGrid` and
+    :class:`XypicDiagramDrawer`.  Returns an Xy-pic presentation of
+    ``diagram``.  The argument ``masked`` is a list of morphisms which
+    will be not be drawn.  The argument ``diagram_format`` is the
+    format string inserted after "\xymatrix".  ``groups`` should be a
+    set of logical groups.  The ``hints`` will be passed directly to
+    the constructor of :class:`DiagramGrid`.
+
+    For more information about the arguments, see the docstrings of
+    :class:`DiagramGrid` and ``XypicDiagramDrawer.draw``.
+
+    Examples
+    ========
+
+    >>> from sympy.categories import Object, NamedMorphism, Diagram
+    >>> from sympy.categories import xypic_draw_diagram
+    >>> A = Object("A")
+    >>> B = Object("B")
+    >>> C = Object("C")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> g = NamedMorphism(B, C, "g")
+    >>> diagram = Diagram([f, g], {g * f: "unique"})
+    >>> print(xypic_draw_diagram(diagram))
+    \xymatrix{
+    A \ar[d]_{g\circ f} \ar[r]^{f} & B \ar[ld]^{g} \\
+    C &
+    }
+
+    See Also
+    ========
+
+    XypicDiagramDrawer, DiagramGrid
+    """
+    grid = DiagramGrid(diagram, groups, **hints)
+    drawer = XypicDiagramDrawer()
+    return drawer.draw(diagram, grid, masked, diagram_format)
+
+
+@doctest_depends_on(exe=('latex', 'dvipng'), modules=('pyglet',))
+def preview_diagram(diagram, masked=None, diagram_format="", groups=None,
+                    output='png', viewer=None, euler=True, **hints):
+    """
+    Combines the functionality of ``xypic_draw_diagram`` and
+    ``sympy.printing.preview``.  The arguments ``masked``,
+    ``diagram_format``, ``groups``, and ``hints`` are passed to
+    ``xypic_draw_diagram``, while ``output``, ``viewer, and ``euler``
+    are passed to ``preview``.
+
+    Examples
+    ========
+
+    >>> from sympy.categories import Object, NamedMorphism, Diagram
+    >>> from sympy.categories import preview_diagram
+    >>> A = Object("A")
+    >>> B = Object("B")
+    >>> C = Object("C")
+    >>> f = NamedMorphism(A, B, "f")
+    >>> g = NamedMorphism(B, C, "g")
+    >>> d = Diagram([f, g], {g * f: "unique"})
+    >>> preview_diagram(d)
+
+    See Also
+    ========
+
+    XypicDiagramDrawer
+    """
+    from sympy.printing import preview
+    latex_output = xypic_draw_diagram(diagram, masked, diagram_format,
+                                      groups, **hints)
+    preview(latex_output, output, viewer, euler, ("xypic",))

.venv/lib/python3.12/site-packages/sympy/categories/tests/test_baseclasses.py

@@ -0,0 +1,209 @@
+from sympy.categories import (Object, Morphism, IdentityMorphism,
+                              NamedMorphism, CompositeMorphism,
+                              Diagram, Category)
+from sympy.categories.baseclasses import Class
+from sympy.testing.pytest import raises
+from sympy.core.containers import (Dict, Tuple)
+from sympy.sets import EmptySet
+from sympy.sets.sets import FiniteSet
+
+
+def test_morphisms():
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+    D = Object("D")
+
+    # Test the base morphism.
+    f = NamedMorphism(A, B, "f")
+    assert f.domain == A
+    assert f.codomain == B
+    assert f == NamedMorphism(A, B, "f")
+
+    # Test identities.
+    id_A = IdentityMorphism(A)
+    id_B = IdentityMorphism(B)
+    assert id_A.domain == A
+    assert id_A.codomain == A
+    assert id_A == IdentityMorphism(A)
+    assert id_A != id_B
+
+    # Test named morphisms.
+    g = NamedMorphism(B, C, "g")
+    assert g.name == "g"
+    assert g != f
+    assert g == NamedMorphism(B, C, "g")
+    assert g != NamedMorphism(B, C, "f")
+
+    # Test composite morphisms.
+    assert f == CompositeMorphism(f)
+
+    k = g.compose(f)
+    assert k.domain == A
+    assert k.codomain == C
+    assert k.components == Tuple(f, g)
+    assert g * f == k
+    assert CompositeMorphism(f, g) == k
+
+    assert CompositeMorphism(g * f) == g * f
+
+    # Test the associativity of composition.
+    h = NamedMorphism(C, D, "h")
+
+    p = h * g
+    u = h * g * f
+
+    assert h * k == u
+    assert p * f == u
+    assert CompositeMorphism(f, g, h) == u
+
+    # Test flattening.
+    u2 = u.flatten("u")
+    assert isinstance(u2, NamedMorphism)
+    assert u2.name == "u"
+    assert u2.domain == A
+    assert u2.codomain == D
+
+    # Test identities.
+    assert f * id_A == f
+    assert id_B * f == f
+    assert id_A * id_A == id_A
+    assert CompositeMorphism(id_A) == id_A
+
+    # Test bad compositions.
+    raises(ValueError, lambda: f * g)
+
+    raises(TypeError, lambda: f.compose(None))
+    raises(TypeError, lambda: id_A.compose(None))
+    raises(TypeError, lambda: f * None)
+    raises(TypeError, lambda: id_A * None)
+
+    raises(TypeError, lambda: CompositeMorphism(f, None, 1))
+
+    raises(ValueError, lambda: NamedMorphism(A, B, ""))
+    raises(NotImplementedError, lambda: Morphism(A, B))
+
+
+def test_diagram():
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+    id_A = IdentityMorphism(A)
+    id_B = IdentityMorphism(B)
+
+    empty = EmptySet
+
+    # Test the addition of identities.
+    d1 = Diagram([f])
+
+    assert d1.objects == FiniteSet(A, B)
+    assert d1.hom(A, B) == (FiniteSet(f), empty)
+    assert d1.hom(A, A) == (FiniteSet(id_A), empty)
+    assert d1.hom(B, B) == (FiniteSet(id_B), empty)
+
+    assert d1 == Diagram([id_A, f])
+    assert d1 == Diagram([f, f])
+
+    # Test the addition of composites.
+    d2 = Diagram([f, g])
+    homAC = d2.hom(A, C)[0]
+
+    assert d2.objects == FiniteSet(A, B, C)
+    assert g * f in d2.premises.keys()
+    assert homAC == FiniteSet(g * f)
+
+    # Test equality, inequality and hash.
+    d11 = Diagram([f])
+
+    assert d1 == d11
+    assert d1 != d2
+    assert hash(d1) == hash(d11)
+
+    d11 = Diagram({f: "unique"})
+    assert d1 != d11
+
+    # Make sure that (re-)adding composites (with new properties)
+    # works as expected.
+    d = Diagram([f, g], {g * f: "unique"})
+    assert d.conclusions == Dict({g * f: FiniteSet("unique")})
+
+    # Check the hom-sets when there are premises and conclusions.
+    assert d.hom(A, C) == (FiniteSet(g * f), FiniteSet(g * f))
+    d = Diagram([f, g], [g * f])
+    assert d.hom(A, C) == (FiniteSet(g * f), FiniteSet(g * f))
+
+    # Check how the properties of composite morphisms are computed.
+    d = Diagram({f: ["unique", "isomorphism"], g: "unique"})
+    assert d.premises[g * f] == FiniteSet("unique")
+
+    # Check that conclusion morphisms with new objects are not allowed.
+    d = Diagram([f], [g])
+    assert d.conclusions == Dict({})
+
+    # Test an empty diagram.
+    d = Diagram()
+    assert d.premises == Dict({})
+    assert d.conclusions == Dict({})
+    assert d.objects == empty
+
+    # Check a SymPy Dict object.
+    d = Diagram(Dict({f: FiniteSet("unique", "isomorphism"), g: "unique"}))
+    assert d.premises[g * f] == FiniteSet("unique")
+
+    # Check the addition of components of composite morphisms.
+    d = Diagram([g * f])
+    assert f in d.premises
+    assert g in d.premises
+
+    # Check subdiagrams.
+    d = Diagram([f, g], {g * f: "unique"})
+
+    d1 = Diagram([f])
+    assert d.is_subdiagram(d1)
+    assert not d1.is_subdiagram(d)
+
+    d = Diagram([NamedMorphism(B, A, "f'")])
+    assert not d.is_subdiagram(d1)
+    assert not d1.is_subdiagram(d)
+
+    d1 = Diagram([f, g], {g * f: ["unique", "something"]})
+    assert not d.is_subdiagram(d1)
+    assert not d1.is_subdiagram(d)
+
+    d = Diagram({f: "blooh"})
+    d1 = Diagram({f: "bleeh"})
+    assert not d.is_subdiagram(d1)
+    assert not d1.is_subdiagram(d)
+
+    d = Diagram([f, g], {f: "unique", g * f: "veryunique"})
+    d1 = d.subdiagram_from_objects(FiniteSet(A, B))
+    assert d1 == Diagram([f], {f: "unique"})
+    raises(ValueError, lambda: d.subdiagram_from_objects(FiniteSet(A,
+           Object("D"))))
+
+    raises(ValueError, lambda: Diagram({IdentityMorphism(A): "unique"}))
+
+
+def test_category():
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+
+    d1 = Diagram([f, g])
+    d2 = Diagram([f])
+
+    objects = d1.objects | d2.objects
+
+    K = Category("K", objects, commutative_diagrams=[d1, d2])
+
+    assert K.name == "K"
+    assert K.objects == Class(objects)
+    assert K.commutative_diagrams == FiniteSet(d1, d2)
+
+    raises(ValueError, lambda: Category(""))

.venv/lib/python3.12/site-packages/sympy/categories/tests/test_drawing.py

@@ -0,0 +1,919 @@
+from sympy.categories.diagram_drawing import _GrowableGrid, ArrowStringDescription
+from sympy.categories import (DiagramGrid, Object, NamedMorphism,
+                              Diagram, XypicDiagramDrawer, xypic_draw_diagram)
+from sympy.sets.sets import FiniteSet
+
+
+def test_GrowableGrid():
+    grid = _GrowableGrid(1, 2)
+
+    # Check dimensions.
+    assert grid.width == 1
+    assert grid.height == 2
+
+    # Check initialization of elements.
+    assert grid[0, 0] is None
+    assert grid[1, 0] is None
+
+    # Check assignment to elements.
+    grid[0, 0] = 1
+    grid[1, 0] = "two"
+
+    assert grid[0, 0] == 1
+    assert grid[1, 0] == "two"
+
+    # Check appending a row.
+    grid.append_row()
+
+    assert grid.width == 1
+    assert grid.height == 3
+
+    assert grid[0, 0] == 1
+    assert grid[1, 0] == "two"
+    assert grid[2, 0] is None
+
+    # Check appending a column.
+    grid.append_column()
+    assert grid.width == 2
+    assert grid.height == 3
+
+    assert grid[0, 0] == 1
+    assert grid[1, 0] == "two"
+    assert grid[2, 0] is None
+
+    assert grid[0, 1] is None
+    assert grid[1, 1] is None
+    assert grid[2, 1] is None
+
+    grid = _GrowableGrid(1, 2)
+    grid[0, 0] = 1
+    grid[1, 0] = "two"
+
+    # Check prepending a row.
+    grid.prepend_row()
+    assert grid.width == 1
+    assert grid.height == 3
+
+    assert grid[0, 0] is None
+    assert grid[1, 0] == 1
+    assert grid[2, 0] == "two"
+
+    # Check prepending a column.
+    grid.prepend_column()
+    assert grid.width == 2
+    assert grid.height == 3
+
+    assert grid[0, 0] is None
+    assert grid[1, 0] is None
+    assert grid[2, 0] is None
+
+    assert grid[0, 1] is None
+    assert grid[1, 1] == 1
+    assert grid[2, 1] == "two"
+
+
+def test_DiagramGrid():
+    # Set up some objects and morphisms.
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+    D = Object("D")
+    E = Object("E")
+
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+    h = NamedMorphism(D, A, "h")
+    k = NamedMorphism(D, B, "k")
+
+    # A one-morphism diagram.
+    d = Diagram([f])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 2
+    assert grid.height == 1
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid.morphisms == {f: FiniteSet()}
+
+    # A triangle.
+    d = Diagram([f, g], {g * f: "unique"})
+    grid = DiagramGrid(d)
+
+    assert grid.width == 2
+    assert grid.height == 2
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[1, 0] == C
+    assert grid[1, 1] is None
+    assert grid.morphisms == {f: FiniteSet(), g: FiniteSet(),
+                              g * f: FiniteSet("unique")}
+
+    # A triangle with a "loop" morphism.
+    l_A = NamedMorphism(A, A, "l_A")
+    d = Diagram([f, g, l_A])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 2
+    assert grid.height == 2
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[1, 0] is None
+    assert grid[1, 1] == C
+    assert grid.morphisms == {f: FiniteSet(), g: FiniteSet(), l_A: FiniteSet()}
+
+    # A simple diagram.
+    d = Diagram([f, g, h, k])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 3
+    assert grid.height == 2
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[0, 2] == D
+    assert grid[1, 0] is None
+    assert grid[1, 1] == C
+    assert grid[1, 2] is None
+    assert grid.morphisms == {f: FiniteSet(), g: FiniteSet(), h: FiniteSet(),
+                              k: FiniteSet()}
+
+    assert str(grid) == '[[Object("A"), Object("B"), Object("D")], ' \
+        '[None, Object("C"), None]]'
+
+    # A chain of morphisms.
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+    h = NamedMorphism(C, D, "h")
+    k = NamedMorphism(D, E, "k")
+    d = Diagram([f, g, h, k])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 3
+    assert grid.height == 3
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[0, 2] is None
+    assert grid[1, 0] is None
+    assert grid[1, 1] == C
+    assert grid[1, 2] == D
+    assert grid[2, 0] is None
+    assert grid[2, 1] is None
+    assert grid[2, 2] == E
+    assert grid.morphisms == {f: FiniteSet(), g: FiniteSet(), h: FiniteSet(),
+                              k: FiniteSet()}
+
+    # A square.
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, D, "g")
+    h = NamedMorphism(A, C, "h")
+    k = NamedMorphism(C, D, "k")
+    d = Diagram([f, g, h, k])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 2
+    assert grid.height == 2
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[1, 0] == C
+    assert grid[1, 1] == D
+    assert grid.morphisms == {f: FiniteSet(), g: FiniteSet(), h: FiniteSet(),
+                              k: FiniteSet()}
+
+    # A strange diagram which resulted from a typo when creating a
+    # test for five lemma, but which allowed to stop one extra problem
+    # in the algorithm.
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+    D = Object("D")
+    E = Object("E")
+    A_ = Object("A'")
+    B_ = Object("B'")
+    C_ = Object("C'")
+    D_ = Object("D'")
+    E_ = Object("E'")
+
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+    h = NamedMorphism(C, D, "h")
+    i = NamedMorphism(D, E, "i")
+
+    # These 4 morphisms should be between primed objects.
+    j = NamedMorphism(A, B, "j")
+    k = NamedMorphism(B, C, "k")
+    l = NamedMorphism(C, D, "l")
+    m = NamedMorphism(D, E, "m")
+
+    o = NamedMorphism(A, A_, "o")
+    p = NamedMorphism(B, B_, "p")
+    q = NamedMorphism(C, C_, "q")
+    r = NamedMorphism(D, D_, "r")
+    s = NamedMorphism(E, E_, "s")
+
+    d = Diagram([f, g, h, i, j, k, l, m, o, p, q, r, s])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 3
+    assert grid.height == 4
+    assert grid[0, 0] is None
+    assert grid[0, 1] == A
+    assert grid[0, 2] == A_
+    assert grid[1, 0] == C
+    assert grid[1, 1] == B
+    assert grid[1, 2] == B_
+    assert grid[2, 0] == C_
+    assert grid[2, 1] == D
+    assert grid[2, 2] == D_
+    assert grid[3, 0] is None
+    assert grid[3, 1] == E
+    assert grid[3, 2] == E_
+
+    morphisms = {}
+    for m in [f, g, h, i, j, k, l, m, o, p, q, r, s]:
+        morphisms[m] = FiniteSet()
+    assert grid.morphisms == morphisms
+
+    # A cube.
+    A1 = Object("A1")
+    A2 = Object("A2")
+    A3 = Object("A3")
+    A4 = Object("A4")
+    A5 = Object("A5")
+    A6 = Object("A6")
+    A7 = Object("A7")
+    A8 = Object("A8")
+
+    # The top face of the cube.
+    f1 = NamedMorphism(A1, A2, "f1")
+    f2 = NamedMorphism(A1, A3, "f2")
+    f3 = NamedMorphism(A2, A4, "f3")
+    f4 = NamedMorphism(A3, A4, "f3")
+
+    # The bottom face of the cube.
+    f5 = NamedMorphism(A5, A6, "f5")
+    f6 = NamedMorphism(A5, A7, "f6")
+    f7 = NamedMorphism(A6, A8, "f7")
+    f8 = NamedMorphism(A7, A8, "f8")
+
+    # The remaining morphisms.
+    f9 = NamedMorphism(A1, A5, "f9")
+    f10 = NamedMorphism(A2, A6, "f10")
+    f11 = NamedMorphism(A3, A7, "f11")
+    f12 = NamedMorphism(A4, A8, "f11")
+
+    d = Diagram([f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11, f12])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 4
+    assert grid.height == 3
+    assert grid[0, 0] is None
+    assert grid[0, 1] == A5
+    assert grid[0, 2] == A6
+    assert grid[0, 3] is None
+    assert grid[1, 0] is None
+    assert grid[1, 1] == A1
+    assert grid[1, 2] == A2
+    assert grid[1, 3] is None
+    assert grid[2, 0] == A7
+    assert grid[2, 1] == A3
+    assert grid[2, 2] == A4
+    assert grid[2, 3] == A8
+
+    morphisms = {}
+    for m in [f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11, f12]:
+        morphisms[m] = FiniteSet()
+    assert grid.morphisms == morphisms
+
+    # A line diagram.
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+    D = Object("D")
+    E = Object("E")
+
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+    h = NamedMorphism(C, D, "h")
+    i = NamedMorphism(D, E, "i")
+    d = Diagram([f, g, h, i])
+    grid = DiagramGrid(d, layout="sequential")
+
+    assert grid.width == 5
+    assert grid.height == 1
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[0, 2] == C
+    assert grid[0, 3] == D
+    assert grid[0, 4] == E
+    assert grid.morphisms == {f: FiniteSet(), g: FiniteSet(), h: FiniteSet(),
+                              i: FiniteSet()}
+
+    # Test the transposed version.
+    grid = DiagramGrid(d, layout="sequential", transpose=True)
+
+    assert grid.width == 1
+    assert grid.height == 5
+    assert grid[0, 0] == A
+    assert grid[1, 0] == B
+    assert grid[2, 0] == C
+    assert grid[3, 0] == D
+    assert grid[4, 0] == E
+    assert grid.morphisms == {f: FiniteSet(), g: FiniteSet(), h: FiniteSet(),
+                              i: FiniteSet()}
+
+    # A pullback.
+    m1 = NamedMorphism(A, B, "m1")
+    m2 = NamedMorphism(A, C, "m2")
+    s1 = NamedMorphism(B, D, "s1")
+    s2 = NamedMorphism(C, D, "s2")
+    f1 = NamedMorphism(E, B, "f1")
+    f2 = NamedMorphism(E, C, "f2")
+    g = NamedMorphism(E, A, "g")
+
+    d = Diagram([m1, m2, s1, s2, f1, f2], {g: "unique"})
+    grid = DiagramGrid(d)
+
+    assert grid.width == 3
+    assert grid.height == 2
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[0, 2] == E
+    assert grid[1, 0] == C
+    assert grid[1, 1] == D
+    assert grid[1, 2] is None
+
+    morphisms = {g: FiniteSet("unique")}
+    for m in [m1, m2, s1, s2, f1, f2]:
+        morphisms[m] = FiniteSet()
+    assert grid.morphisms == morphisms
+
+    # Test the pullback with sequential layout, just for stress
+    # testing.
+    grid = DiagramGrid(d, layout="sequential")
+
+    assert grid.width == 5
+    assert grid.height == 1
+    assert grid[0, 0] == D
+    assert grid[0, 1] == B
+    assert grid[0, 2] == A
+    assert grid[0, 3] == C
+    assert grid[0, 4] == E
+    assert grid.morphisms == morphisms
+
+    # Test a pullback with object grouping.
+    grid = DiagramGrid(d, groups=FiniteSet(E, FiniteSet(A, B, C, D)))
+
+    assert grid.width == 3
+    assert grid.height == 2
+    assert grid[0, 0] == E
+    assert grid[0, 1] == A
+    assert grid[0, 2] == B
+    assert grid[1, 0] is None
+    assert grid[1, 1] == C
+    assert grid[1, 2] == D
+    assert grid.morphisms == morphisms
+
+    # Five lemma, actually.
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+    D = Object("D")
+    E = Object("E")
+    A_ = Object("A'")
+    B_ = Object("B'")
+    C_ = Object("C'")
+    D_ = Object("D'")
+    E_ = Object("E'")
+
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+    h = NamedMorphism(C, D, "h")
+    i = NamedMorphism(D, E, "i")
+
+    j = NamedMorphism(A_, B_, "j")
+    k = NamedMorphism(B_, C_, "k")
+    l = NamedMorphism(C_, D_, "l")
+    m = NamedMorphism(D_, E_, "m")
+
+    o = NamedMorphism(A, A_, "o")
+    p = NamedMorphism(B, B_, "p")
+    q = NamedMorphism(C, C_, "q")
+    r = NamedMorphism(D, D_, "r")
+    s = NamedMorphism(E, E_, "s")
+
+    d = Diagram([f, g, h, i, j, k, l, m, o, p, q, r, s])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 5
+    assert grid.height == 3
+    assert grid[0, 0] is None
+    assert grid[0, 1] == A
+    assert grid[0, 2] == A_
+    assert grid[0, 3] is None
+    assert grid[0, 4] is None
+    assert grid[1, 0] == C
+    assert grid[1, 1] == B
+    assert grid[1, 2] == B_
+    assert grid[1, 3] == C_
+    assert grid[1, 4] is None
+    assert grid[2, 0] == D
+    assert grid[2, 1] == E
+    assert grid[2, 2] is None
+    assert grid[2, 3] == D_
+    assert grid[2, 4] == E_
+
+    morphisms = {}
+    for m in [f, g, h, i, j, k, l, m, o, p, q, r, s]:
+        morphisms[m] = FiniteSet()
+    assert grid.morphisms == morphisms
+
+    # Test the five lemma with object grouping.
+    grid = DiagramGrid(d, FiniteSet(
+        FiniteSet(A, B, C, D, E), FiniteSet(A_, B_, C_, D_, E_)))
+
+    assert grid.width == 6
+    assert grid.height == 3
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[0, 2] is None
+    assert grid[0, 3] == A_
+    assert grid[0, 4] == B_
+    assert grid[0, 5] is None
+    assert grid[1, 0] is None
+    assert grid[1, 1] == C
+    assert grid[1, 2] == D
+    assert grid[1, 3] is None
+    assert grid[1, 4] == C_
+    assert grid[1, 5] == D_
+    assert grid[2, 0] is None
+    assert grid[2, 1] is None
+    assert grid[2, 2] == E
+    assert grid[2, 3] is None
+    assert grid[2, 4] is None
+    assert grid[2, 5] == E_
+    assert grid.morphisms == morphisms
+
+    # Test the five lemma with object grouping, but mixing containers
+    # to represent groups.
+    grid = DiagramGrid(d, [(A, B, C, D, E), {A_, B_, C_, D_, E_}])
+
+    assert grid.width == 6
+    assert grid.height == 3
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[0, 2] is None
+    assert grid[0, 3] == A_
+    assert grid[0, 4] == B_
+    assert grid[0, 5] is None
+    assert grid[1, 0] is None
+    assert grid[1, 1] == C
+    assert grid[1, 2] == D
+    assert grid[1, 3] is None
+    assert grid[1, 4] == C_
+    assert grid[1, 5] == D_
+    assert grid[2, 0] is None
+    assert grid[2, 1] is None
+    assert grid[2, 2] == E
+    assert grid[2, 3] is None
+    assert grid[2, 4] is None
+    assert grid[2, 5] == E_
+    assert grid.morphisms == morphisms
+
+    # Test the five lemma with object grouping and hints.
+    grid = DiagramGrid(d, {
+        FiniteSet(A, B, C, D, E): {"layout": "sequential",
+                                   "transpose": True},
+        FiniteSet(A_, B_, C_, D_, E_): {"layout": "sequential",
+                                        "transpose": True}},
+        transpose=True)
+
+    assert grid.width == 5
+    assert grid.height == 2
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[0, 2] == C
+    assert grid[0, 3] == D
+    assert grid[0, 4] == E
+    assert grid[1, 0] == A_
+    assert grid[1, 1] == B_
+    assert grid[1, 2] == C_
+    assert grid[1, 3] == D_
+    assert grid[1, 4] == E_
+    assert grid.morphisms == morphisms
+
+    # A two-triangle disconnected diagram.
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+    f_ = NamedMorphism(A_, B_, "f")
+    g_ = NamedMorphism(B_, C_, "g")
+    d = Diagram([f, g, f_, g_], {g * f: "unique", g_ * f_: "unique"})
+    grid = DiagramGrid(d)
+
+    assert grid.width == 4
+    assert grid.height == 2
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[0, 2] == A_
+    assert grid[0, 3] == B_
+    assert grid[1, 0] == C
+    assert grid[1, 1] is None
+    assert grid[1, 2] == C_
+    assert grid[1, 3] is None
+    assert grid.morphisms == {f: FiniteSet(), g: FiniteSet(), f_: FiniteSet(),
+                              g_: FiniteSet(), g * f: FiniteSet("unique"),
+                              g_ * f_: FiniteSet("unique")}
+
+    # A two-morphism disconnected diagram.
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(C, D, "g")
+    d = Diagram([f, g])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 4
+    assert grid.height == 1
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+    assert grid[0, 2] == C
+    assert grid[0, 3] == D
+    assert grid.morphisms == {f: FiniteSet(), g: FiniteSet()}
+
+    # Test a one-object diagram.
+    f = NamedMorphism(A, A, "f")
+    d = Diagram([f])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 1
+    assert grid.height == 1
+    assert grid[0, 0] == A
+
+    # Test a two-object disconnected diagram.
+    g = NamedMorphism(B, B, "g")
+    d = Diagram([f, g])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 2
+    assert grid.height == 1
+    assert grid[0, 0] == A
+    assert grid[0, 1] == B
+
+
+def test_DiagramGrid_pseudopod():
+    # Test a diagram in which even growing a pseudopod does not
+    # eventually help.
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+    D = Object("D")
+    E = Object("E")
+    F = Object("F")
+    A_ = Object("A'")
+    B_ = Object("B'")
+    C_ = Object("C'")
+    D_ = Object("D'")
+    E_ = Object("E'")
+
+    f1 = NamedMorphism(A, B, "f1")
+    f2 = NamedMorphism(A, C, "f2")
+    f3 = NamedMorphism(A, D, "f3")
+    f4 = NamedMorphism(A, E, "f4")
+    f5 = NamedMorphism(A, A_, "f5")
+    f6 = NamedMorphism(A, B_, "f6")
+    f7 = NamedMorphism(A, C_, "f7")
+    f8 = NamedMorphism(A, D_, "f8")
+    f9 = NamedMorphism(A, E_, "f9")
+    f10 = NamedMorphism(A, F, "f10")
+    d = Diagram([f1, f2, f3, f4, f5, f6, f7, f8, f9, f10])
+    grid = DiagramGrid(d)
+
+    assert grid.width == 5
+    assert grid.height == 3
+    assert grid[0, 0] == E
+    assert grid[0, 1] == C
+    assert grid[0, 2] == C_
+    assert grid[0, 3] == E_
+    assert grid[0, 4] == F
+    assert grid[1, 0] == D
+    assert grid[1, 1] == A
+    assert grid[1, 2] == A_
+    assert grid[1, 3] is None
+    assert grid[1, 4] is None
+    assert grid[2, 0] == D_
+    assert grid[2, 1] == B
+    assert grid[2, 2] == B_
+    assert grid[2, 3] is None
+    assert grid[2, 4] is None
+
+    morphisms = {}
+    for f in [f1, f2, f3, f4, f5, f6, f7, f8, f9, f10]:
+        morphisms[f] = FiniteSet()
+    assert grid.morphisms == morphisms
+
+
+def test_ArrowStringDescription():
+    astr = ArrowStringDescription("cm", "", None, "", "", "d", "r", "_", "f")
+    assert str(astr) == "\\ar[dr]_{f}"
+
+    astr = ArrowStringDescription("cm", "", 12, "", "", "d", "r", "_", "f")
+    assert str(astr) == "\\ar[dr]_{f}"
+
+    astr = ArrowStringDescription("cm", "^", 12, "", "", "d", "r", "_", "f")
+    assert str(astr) == "\\ar@/^12cm/[dr]_{f}"
+
+    astr = ArrowStringDescription("cm", "", 12, "r", "", "d", "r", "_", "f")
+    assert str(astr) == "\\ar[dr]_{f}"
+
+    astr = ArrowStringDescription("cm", "", 12, "r", "u", "d", "r", "_", "f")
+    assert str(astr) == "\\ar@(r,u)[dr]_{f}"
+
+    astr = ArrowStringDescription("cm", "", 12, "r", "u", "d", "r", "_", "f")
+    assert str(astr) == "\\ar@(r,u)[dr]_{f}"
+
+    astr = ArrowStringDescription("cm", "", 12, "r", "u", "d", "r", "_", "f")
+    astr.arrow_style = "{-->}"
+    assert str(astr) == "\\ar@(r,u)@{-->}[dr]_{f}"
+
+    astr = ArrowStringDescription("cm", "_", 12, "", "", "d", "r", "_", "f")
+    astr.arrow_style = "{-->}"
+    assert str(astr) == "\\ar@/_12cm/@{-->}[dr]_{f}"
+
+
+def test_XypicDiagramDrawer_line():
+    # A linear diagram.
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+    D = Object("D")
+    E = Object("E")
+
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+    h = NamedMorphism(C, D, "h")
+    i = NamedMorphism(D, E, "i")
+    d = Diagram([f, g, h, i])
+    grid = DiagramGrid(d, layout="sequential")
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[r]^{f} & B \\ar[r]^{g} & C \\ar[r]^{h} & D \\ar[r]^{i} & E \n" \
+        "}\n"
+
+    # The same diagram, transposed.
+    grid = DiagramGrid(d, layout="sequential", transpose=True)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[d]^{f} \\\\\n" \
+        "B \\ar[d]^{g} \\\\\n" \
+        "C \\ar[d]^{h} \\\\\n" \
+        "D \\ar[d]^{i} \\\\\n" \
+        "E \n" \
+        "}\n"
+
+
+def test_XypicDiagramDrawer_triangle():
+    # A triangle diagram.
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+
+    d = Diagram([f, g], {g * f: "unique"})
+    grid = DiagramGrid(d)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[d]_{g\\circ f} \\ar[r]^{f} & B \\ar[ld]^{g} \\\\\n" \
+        "C & \n" \
+        "}\n"
+
+    # The same diagram, transposed.
+    grid = DiagramGrid(d, transpose=True)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[r]^{g\\circ f} \\ar[d]_{f} & C \\\\\n" \
+        "B \\ar[ru]_{g} & \n" \
+        "}\n"
+
+    # The same diagram, with a masked morphism.
+    assert drawer.draw(d, grid, masked=[g]) == "\\xymatrix{\n" \
+        "A \\ar[r]^{g\\circ f} \\ar[d]_{f} & C \\\\\n" \
+        "B & \n" \
+        "}\n"
+
+    # The same diagram with a formatter for "unique".
+    def formatter(astr):
+        astr.label = "\\exists !" + astr.label
+        astr.arrow_style = "{-->}"
+
+    drawer.arrow_formatters["unique"] = formatter
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar@{-->}[r]^{\\exists !g\\circ f} \\ar[d]_{f} & C \\\\\n" \
+        "B \\ar[ru]_{g} & \n" \
+        "}\n"
+
+    # The same diagram with a default formatter.
+    def default_formatter(astr):
+        astr.label_displacement = "(0.45)"
+
+    drawer.default_arrow_formatter = default_formatter
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar@{-->}[r]^(0.45){\\exists !g\\circ f} \\ar[d]_(0.45){f} & C \\\\\n" \
+        "B \\ar[ru]_(0.45){g} & \n" \
+        "}\n"
+
+    # A triangle diagram with a lot of morphisms between the same
+    # objects.
+    f1 = NamedMorphism(B, A, "f1")
+    f2 = NamedMorphism(A, B, "f2")
+    g1 = NamedMorphism(C, B, "g1")
+    g2 = NamedMorphism(B, C, "g2")
+    d = Diagram([f, f1, f2, g, g1, g2], {f1 * g1: "unique", g2 * f2: "unique"})
+
+    grid = DiagramGrid(d, transpose=True)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid, masked=[f1*g1*g2*f2, g2*f2*f1*g1]) == \
+        "\\xymatrix{\n" \
+        "A \\ar[r]^{g_{2}\\circ f_{2}} \\ar[d]_{f} \\ar@/^3mm/[d]^{f_{2}} " \
+        "& C \\ar@/^3mm/[l]^{f_{1}\\circ g_{1}} \\ar@/^3mm/[ld]^{g_{1}} \\\\\n" \
+        "B \\ar@/^3mm/[u]^{f_{1}} \\ar[ru]_{g} \\ar@/^3mm/[ru]^{g_{2}} & \n" \
+        "}\n"
+
+
+def test_XypicDiagramDrawer_cube():
+    # A cube diagram.
+    A1 = Object("A1")
+    A2 = Object("A2")
+    A3 = Object("A3")
+    A4 = Object("A4")
+    A5 = Object("A5")
+    A6 = Object("A6")
+    A7 = Object("A7")
+    A8 = Object("A8")
+
+    # The top face of the cube.
+    f1 = NamedMorphism(A1, A2, "f1")
+    f2 = NamedMorphism(A1, A3, "f2")
+    f3 = NamedMorphism(A2, A4, "f3")
+    f4 = NamedMorphism(A3, A4, "f3")
+
+    # The bottom face of the cube.
+    f5 = NamedMorphism(A5, A6, "f5")
+    f6 = NamedMorphism(A5, A7, "f6")
+    f7 = NamedMorphism(A6, A8, "f7")
+    f8 = NamedMorphism(A7, A8, "f8")
+
+    # The remaining morphisms.
+    f9 = NamedMorphism(A1, A5, "f9")
+    f10 = NamedMorphism(A2, A6, "f10")
+    f11 = NamedMorphism(A3, A7, "f11")
+    f12 = NamedMorphism(A4, A8, "f11")
+
+    d = Diagram([f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11, f12])
+    grid = DiagramGrid(d)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "& A_{5} \\ar[r]^{f_{5}} \\ar[ldd]_{f_{6}} & A_{6} \\ar[rdd]^{f_{7}} " \
+        "& \\\\\n" \
+        "& A_{1} \\ar[r]^{f_{1}} \\ar[d]^{f_{2}} \\ar[u]^{f_{9}} & A_{2} " \
+        "\\ar[d]^{f_{3}} \\ar[u]_{f_{10}} & \\\\\n" \
+        "A_{7} \\ar@/_3mm/[rrr]_{f_{8}} & A_{3} \\ar[r]^{f_{3}} \\ar[l]_{f_{11}} " \
+        "& A_{4} \\ar[r]^{f_{11}} & A_{8} \n" \
+        "}\n"
+
+    # The same diagram, transposed.
+    grid = DiagramGrid(d, transpose=True)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "& & A_{7} \\ar@/^3mm/[ddd]^{f_{8}} \\\\\n" \
+        "A_{5} \\ar[d]_{f_{5}} \\ar[rru]^{f_{6}} & A_{1} \\ar[d]^{f_{1}} " \
+        "\\ar[r]^{f_{2}} \\ar[l]^{f_{9}} & A_{3} \\ar[d]_{f_{3}} " \
+        "\\ar[u]^{f_{11}} \\\\\n" \
+        "A_{6} \\ar[rrd]_{f_{7}} & A_{2} \\ar[r]^{f_{3}} \\ar[l]^{f_{10}} " \
+        "& A_{4} \\ar[d]_{f_{11}} \\\\\n" \
+        "& & A_{8} \n" \
+        "}\n"
+
+
+def test_XypicDiagramDrawer_curved_and_loops():
+    # A simple diagram, with a curved arrow.
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+    D = Object("D")
+
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+    h = NamedMorphism(D, A, "h")
+    k = NamedMorphism(D, B, "k")
+    d = Diagram([f, g, h, k])
+    grid = DiagramGrid(d)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[r]_{f} & B \\ar[d]^{g} & D \\ar[l]^{k} \\ar@/_3mm/[ll]_{h} \\\\\n" \
+        "& C & \n" \
+        "}\n"
+
+    # The same diagram, transposed.
+    grid = DiagramGrid(d, transpose=True)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[d]^{f} & \\\\\n" \
+        "B \\ar[r]^{g} & C \\\\\n" \
+        "D \\ar[u]_{k} \\ar@/^3mm/[uu]^{h} & \n" \
+        "}\n"
+
+    # The same diagram, larger and rotated.
+    assert drawer.draw(d, grid, diagram_format="@+1cm@dr") == \
+        "\\xymatrix@+1cm@dr{\n" \
+        "A \\ar[d]^{f} & \\\\\n" \
+        "B \\ar[r]^{g} & C \\\\\n" \
+        "D \\ar[u]_{k} \\ar@/^3mm/[uu]^{h} & \n" \
+        "}\n"
+
+    # A simple diagram with three curved arrows.
+    h1 = NamedMorphism(D, A, "h1")
+    h2 = NamedMorphism(A, D, "h2")
+    k = NamedMorphism(D, B, "k")
+    d = Diagram([f, g, h, k, h1, h2])
+    grid = DiagramGrid(d)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[r]_{f} \\ar@/^3mm/[rr]^{h_{2}} & B \\ar[d]^{g} & D \\ar[l]^{k} " \
+        "\\ar@/_7mm/[ll]_{h} \\ar@/_11mm/[ll]_{h_{1}} \\\\\n" \
+        "& C & \n" \
+        "}\n"
+
+    # The same diagram, transposed.
+    grid = DiagramGrid(d, transpose=True)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[d]^{f} \\ar@/_3mm/[dd]_{h_{2}} & \\\\\n" \
+        "B \\ar[r]^{g} & C \\\\\n" \
+        "D \\ar[u]_{k} \\ar@/^7mm/[uu]^{h} \\ar@/^11mm/[uu]^{h_{1}} & \n" \
+        "}\n"
+
+    # The same diagram, with "loop" morphisms.
+    l_A = NamedMorphism(A, A, "l_A")
+    l_D = NamedMorphism(D, D, "l_D")
+    l_C = NamedMorphism(C, C, "l_C")
+    d = Diagram([f, g, h, k, h1, h2, l_A, l_D, l_C])
+    grid = DiagramGrid(d)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[r]_{f} \\ar@/^3mm/[rr]^{h_{2}} \\ar@(u,l)[]^{l_{A}} " \
+        "& B \\ar[d]^{g} & D \\ar[l]^{k} \\ar@/_7mm/[ll]_{h} " \
+        "\\ar@/_11mm/[ll]_{h_{1}} \\ar@(r,u)[]^{l_{D}} \\\\\n" \
+        "& C \\ar@(l,d)[]^{l_{C}} & \n" \
+        "}\n"
+
+    # The same diagram with "loop" morphisms, transposed.
+    grid = DiagramGrid(d, transpose=True)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[d]^{f} \\ar@/_3mm/[dd]_{h_{2}} \\ar@(r,u)[]^{l_{A}} & \\\\\n" \
+        "B \\ar[r]^{g} & C \\ar@(r,u)[]^{l_{C}} \\\\\n" \
+        "D \\ar[u]_{k} \\ar@/^7mm/[uu]^{h} \\ar@/^11mm/[uu]^{h_{1}} " \
+        "\\ar@(l,d)[]^{l_{D}} & \n" \
+        "}\n"
+
+    # The same diagram with two "loop" morphisms per object.
+    l_A_ = NamedMorphism(A, A, "n_A")
+    l_D_ = NamedMorphism(D, D, "n_D")
+    l_C_ = NamedMorphism(C, C, "n_C")
+    d = Diagram([f, g, h, k, h1, h2, l_A, l_D, l_C, l_A_, l_D_, l_C_])
+    grid = DiagramGrid(d)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[r]_{f} \\ar@/^3mm/[rr]^{h_{2}} \\ar@(u,l)[]^{l_{A}} " \
+        "\\ar@/^3mm/@(l,d)[]^{n_{A}} & B \\ar[d]^{g} & D \\ar[l]^{k} " \
+        "\\ar@/_7mm/[ll]_{h} \\ar@/_11mm/[ll]_{h_{1}} \\ar@(r,u)[]^{l_{D}} " \
+        "\\ar@/^3mm/@(d,r)[]^{n_{D}} \\\\\n" \
+        "& C \\ar@(l,d)[]^{l_{C}} \\ar@/^3mm/@(d,r)[]^{n_{C}} & \n" \
+        "}\n"
+
+    # The same diagram with two "loop" morphisms per object, transposed.
+    grid = DiagramGrid(d, transpose=True)
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == "\\xymatrix{\n" \
+        "A \\ar[d]^{f} \\ar@/_3mm/[dd]_{h_{2}} \\ar@(r,u)[]^{l_{A}} " \
+        "\\ar@/^3mm/@(u,l)[]^{n_{A}} & \\\\\n" \
+        "B \\ar[r]^{g} & C \\ar@(r,u)[]^{l_{C}} \\ar@/^3mm/@(d,r)[]^{n_{C}} \\\\\n" \
+        "D \\ar[u]_{k} \\ar@/^7mm/[uu]^{h} \\ar@/^11mm/[uu]^{h_{1}} " \
+        "\\ar@(l,d)[]^{l_{D}} \\ar@/^3mm/@(d,r)[]^{n_{D}} & \n" \
+        "}\n"
+
+
+def test_xypic_draw_diagram():
+    # A linear diagram.
+    A = Object("A")
+    B = Object("B")
+    C = Object("C")
+    D = Object("D")
+    E = Object("E")
+
+    f = NamedMorphism(A, B, "f")
+    g = NamedMorphism(B, C, "g")
+    h = NamedMorphism(C, D, "h")
+    i = NamedMorphism(D, E, "i")
+    d = Diagram([f, g, h, i])
+
+    grid = DiagramGrid(d, layout="sequential")
+    drawer = XypicDiagramDrawer()
+    assert drawer.draw(d, grid) == xypic_draw_diagram(d, layout="sequential")

.venv/lib/python3.12/site-packages/sympy/codegen/__init__.py

@@ -0,0 +1,24 @@
+""" The ``sympy.codegen`` module contains classes and functions for building
+abstract syntax trees of algorithms. These trees may then be printed by the
+code-printers in ``sympy.printing``.
+
+There are several submodules available:
+- ``sympy.codegen.ast``: AST nodes useful across multiple languages.
+- ``sympy.codegen.cnodes``: AST nodes useful for the C family of languages.
+- ``sympy.codegen.fnodes``: AST nodes useful for Fortran.
+- ``sympy.codegen.cfunctions``: functions specific to C (C99 math functions)
+- ``sympy.codegen.ffunctions``: functions specific to Fortran (e.g. ``kind``).
+
+
+
+"""
+from .ast import (
+    Assignment, aug_assign, CodeBlock, For, Attribute, Variable, Declaration,
+    While, Scope, Print, FunctionPrototype, FunctionDefinition, FunctionCall
+)
+
+__all__ = [
+    'Assignment', 'aug_assign', 'CodeBlock', 'For', 'Attribute', 'Variable',
+    'Declaration', 'While', 'Scope', 'Print', 'FunctionPrototype',
+    'FunctionDefinition', 'FunctionCall',
+]

.venv/lib/python3.12/site-packages/sympy/codegen/abstract_nodes.py

@@ -0,0 +1,18 @@
+"""This module provides containers for python objects that are valid
+printing targets but are not a subclass of SymPy's Printable.
+"""
+
+
+from sympy.core.containers import Tuple
+
+
+class List(Tuple):
+    """Represents a (frozen) (Python) list (for code printing purposes)."""
+    def __eq__(self, other):
+        if isinstance(other, list):
+            return self == List(*other)
+        else:
+            return self.args == other
+
+    def __hash__(self):
+        return super().__hash__()

.venv/lib/python3.12/site-packages/sympy/codegen/algorithms.py

@@ -0,0 +1,180 @@
+from sympy.core.containers import Tuple
+from sympy.core.numbers import oo
+from sympy.core.relational import (Gt, Lt)
+from sympy.core.symbol import (Dummy, Symbol)
+from sympy.functions.elementary.complexes import Abs
+from sympy.functions.elementary.miscellaneous import Min, Max
+from sympy.logic.boolalg import And
+from sympy.codegen.ast import (
+    Assignment, AddAugmentedAssignment, break_, CodeBlock, Declaration, FunctionDefinition,
+    Print, Return, Scope, While, Variable, Pointer, real
+)
+from sympy.codegen.cfunctions import isnan
+
+""" This module collects functions for constructing ASTs representing algorithms. """
+
+def newtons_method(expr, wrt, atol=1e-12, delta=None, *, rtol=4e-16, debug=False,
+                   itermax=None, counter=None, delta_fn=lambda e, x: -e/e.diff(x),
+                   cse=False, handle_nan=None,
+                   bounds=None):
+    """ Generates an AST for Newton-Raphson method (a root-finding algorithm).
+
+    Explanation
+    ===========
+
+    Returns an abstract syntax tree (AST) based on ``sympy.codegen.ast`` for Netwon's
+    method of root-finding.
+
+    Parameters
+    ==========
+
+    expr : expression
+    wrt : Symbol
+        With respect to, i.e. what is the variable.
+    atol : number or expression
+        Absolute tolerance (stopping criterion)
+    rtol : number or expression
+        Relative tolerance (stopping criterion)
+    delta : Symbol
+        Will be a ``Dummy`` if ``None``.
+    debug : bool
+        Whether to print convergence information during iterations
+    itermax : number or expr
+        Maximum number of iterations.
+    counter : Symbol
+        Will be a ``Dummy`` if ``None``.
+    delta_fn: Callable[[Expr, Symbol], Expr]
+        computes the step, default is newtons method. For e.g. Halley's method
+        use delta_fn=lambda e, x: -2*e*e.diff(x)/(2*e.diff(x)**2 - e*e.diff(x, 2))
+    cse: bool
+        Perform common sub-expression elimination on delta expression
+    handle_nan: Token
+        How to handle occurrence of not-a-number (NaN).
+    bounds: Optional[tuple[Expr, Expr]]
+        Perform optimization within bounds
+
+    Examples
+    ========
+
+    >>> from sympy import symbols, cos
+    >>> from sympy.codegen.ast import Assignment
+    >>> from sympy.codegen.algorithms import newtons_method
+    >>> x, dx, atol = symbols('x dx atol')
+    >>> expr = cos(x) - x**3
+    >>> algo = newtons_method(expr, x, atol=atol, delta=dx)
+    >>> algo.has(Assignment(dx, -expr/expr.diff(x)))
+    True
+
+    References
+    ==========
+
+    .. [1] https://en.wikipedia.org/wiki/Newton%27s_method
+
+    """
+
+    if delta is None:
+        delta = Dummy()
+        Wrapper = Scope
+        name_d = 'delta'
+    else:
+        Wrapper = lambda x: x
+        name_d = delta.name
+
+    delta_expr = delta_fn(expr, wrt)
+    if cse:
+        from sympy.simplify.cse_main import cse
+        cses, (red,) = cse([delta_expr.factor()])
+        whl_bdy = [Assignment(dum, sub_e) for dum, sub_e in cses]
+        whl_bdy += [Assignment(delta, red)]
+    else:
+        whl_bdy = [Assignment(delta, delta_expr)]
+    if handle_nan is not None:
+        whl_bdy += [While(isnan(delta), CodeBlock(handle_nan, break_))]
+    whl_bdy += [AddAugmentedAssignment(wrt, delta)]
+    if bounds is not None:
+        whl_bdy += [Assignment(wrt, Min(Max(wrt, bounds[0]), bounds[1]))]
+    if debug:
+        prnt = Print([wrt, delta], r"{}=%12.5g {}=%12.5g\n".format(wrt.name, name_d))
+        whl_bdy += [prnt]
+    req = Gt(Abs(delta), atol + rtol*Abs(wrt))
+    declars = [Declaration(Variable(delta, type=real, value=oo))]
+    if itermax is not None:
+        counter = counter or Dummy(integer=True)
+        v_counter = Variable.deduced(counter, 0)
+        declars.append(Declaration(v_counter))
+        whl_bdy.append(AddAugmentedAssignment(counter, 1))
+        req = And(req, Lt(counter, itermax))
+    whl = While(req, CodeBlock(*whl_bdy))
+    blck = declars
+    if debug:
+        blck.append(Print([wrt], r"{}=%12.5g\n".format(wrt.name)))
+    blck += [whl]
+    return Wrapper(CodeBlock(*blck))
+
+
+def _symbol_of(arg):
+    if isinstance(arg, Declaration):
+        arg = arg.variable.symbol
+    elif isinstance(arg, Variable):
+        arg = arg.symbol
+    return arg
+
+
+def newtons_method_function(expr, wrt, params=None, func_name="newton", attrs=Tuple(), *, delta=None, **kwargs):
+    """ Generates an AST for a function implementing the Newton-Raphson method.
+
+    Parameters
+    ==========
+
+    expr : expression
+    wrt : Symbol
+        With respect to, i.e. what is the variable
+    params : iterable of symbols
+        Symbols appearing in expr that are taken as constants during the iterations
+        (these will be accepted as parameters to the generated function).
+    func_name : str
+        Name of the generated function.
+    attrs : Tuple
+        Attribute instances passed as ``attrs`` to ``FunctionDefinition``.
+    \\*\\*kwargs :
+        Keyword arguments passed to :func:`sympy.codegen.algorithms.newtons_method`.
+
+    Examples
+    ========
+
+    >>> from sympy import symbols, cos
+    >>> from sympy.codegen.algorithms import newtons_method_function
+    >>> from sympy.codegen.pyutils import render_as_module
+    >>> x = symbols('x')
+    >>> expr = cos(x) - x**3
+    >>> func = newtons_method_function(expr, x)
+    >>> py_mod = render_as_module(func)  # source code as string
+    >>> namespace = {}
+    >>> exec(py_mod, namespace, namespace)
+    >>> res = eval('newton(0.5)', namespace)
+    >>> abs(res - 0.865474033102) < 1e-12
+    True
+
+    See Also
+    ========
+
+    sympy.codegen.algorithms.newtons_method
+
+    """
+    if params is None:
+        params = (wrt,)
+    pointer_subs = {p.symbol: Symbol('(*%s)' % p.symbol.name)
+                    for p in params if isinstance(p, Pointer)}
+    if delta is None:
+        delta = Symbol('d_' + wrt.name)
+        if expr.has(delta):
+            delta = None  # will use Dummy
+    algo = newtons_method(expr, wrt, delta=delta, **kwargs).xreplace(pointer_subs)
+    if isinstance(algo, Scope):
+        algo = algo.body
+    not_in_params = expr.free_symbols.difference({_symbol_of(p) for p in params})
+    if not_in_params:
+        raise ValueError("Missing symbols in params: %s" % ', '.join(map(str, not_in_params)))
+    declars = tuple(Variable(p, real) for p in params)
+    body = CodeBlock(algo, Return(wrt))
+    return FunctionDefinition(real, func_name, declars, body, attrs=attrs)

.venv/lib/python3.12/site-packages/sympy/codegen/approximations.py

@@ -0,0 +1,187 @@
+import math
+from sympy.sets.sets import Interval
+from sympy.calculus.singularities import is_increasing, is_decreasing
+from sympy.codegen.rewriting import Optimization
+from sympy.core.function import UndefinedFunction
+
+"""
+This module collects classes useful for approximate rewriting of expressions.
+This can be beneficial when generating numeric code for which performance is
+of greater importance than precision (e.g. for preconditioners used in iterative
+methods).
+"""
+
+class SumApprox(Optimization):
+    """
+    Approximates sum by neglecting small terms.
+
+    Explanation
+    ===========
+
+    If terms are expressions which can be determined to be monotonic, then
+    bounds for those expressions are added.
+
+    Parameters
+    ==========
+
+    bounds : dict
+        Mapping expressions to length 2 tuple of bounds (low, high).
+    reltol : number
+        Threshold for when to ignore a term. Taken relative to the largest
+        lower bound among bounds.
+
+    Examples
+    ========
+
+    >>> from sympy import exp
+    >>> from sympy.abc import x, y, z
+    >>> from sympy.codegen.rewriting import optimize
+    >>> from sympy.codegen.approximations import SumApprox
+    >>> bounds = {x: (-1, 1), y: (1000, 2000), z: (-10, 3)}
+    >>> sum_approx3 = SumApprox(bounds, reltol=1e-3)
+    >>> sum_approx2 = SumApprox(bounds, reltol=1e-2)
+    >>> sum_approx1 = SumApprox(bounds, reltol=1e-1)
+    >>> expr = 3*(x + y + exp(z))
+    >>> optimize(expr, [sum_approx3])
+    3*(x + y + exp(z))
+    >>> optimize(expr, [sum_approx2])
+    3*y + 3*exp(z)
+    >>> optimize(expr, [sum_approx1])
+    3*y
+
+    """
+
+    def __init__(self, bounds, reltol, **kwargs):
+        super().__init__(**kwargs)
+        self.bounds = bounds
+        self.reltol = reltol
+
+    def __call__(self, expr):
+        return expr.factor().replace(self.query, lambda arg: self.value(arg))
+
+    def query(self, expr):
+        return expr.is_Add
+
+    def value(self, add):
+        for term in add.args:
+            if term.is_number or term in self.bounds or len(term.free_symbols) != 1:
+                continue
+            fs, = term.free_symbols
+            if fs not in self.bounds:
+                continue
+            intrvl = Interval(*self.bounds[fs])
+            if is_increasing(term, intrvl, fs):
+                self.bounds[term] = (
+                    term.subs({fs: self.bounds[fs][0]}),
+                    term.subs({fs: self.bounds[fs][1]})
+                )
+            elif is_decreasing(term, intrvl, fs):
+                self.bounds[term] = (
+                    term.subs({fs: self.bounds[fs][1]}),
+                    term.subs({fs: self.bounds[fs][0]})
+                )
+            else:
+                return add
+
+        if all(term.is_number or term in self.bounds for term in add.args):
+            bounds = [(term, term) if term.is_number else self.bounds[term] for term in add.args]
+            largest_abs_guarantee = 0
+            for lo, hi in bounds:
+                if lo <= 0 <= hi:
+                    continue
+                largest_abs_guarantee = max(largest_abs_guarantee,
+                                            min(abs(lo), abs(hi)))
+            new_terms = []
+            for term, (lo, hi) in zip(add.args, bounds):
+                if max(abs(lo), abs(hi)) >= largest_abs_guarantee*self.reltol:
+                    new_terms.append(term)
+            return add.func(*new_terms)
+        else:
+            return add
+
+
+class SeriesApprox(Optimization):
+    """ Approximates functions by expanding them as a series.
+
+    Parameters
+    ==========
+
+    bounds : dict
+        Mapping expressions to length 2 tuple of bounds (low, high).
+    reltol : number
+        Threshold for when to ignore a term. Taken relative to the largest
+        lower bound among bounds.
+    max_order : int
+        Largest order to include in series expansion
+    n_point_checks : int (even)
+        The validity of an expansion (with respect to reltol) is checked at
+        discrete points (linearly spaced over the bounds of the variable). The
+        number of points used in this numerical check is given by this number.
+
+    Examples
+    ========
+
+    >>> from sympy import sin, pi
+    >>> from sympy.abc import x, y
+    >>> from sympy.codegen.rewriting import optimize
+    >>> from sympy.codegen.approximations import SeriesApprox
+    >>> bounds = {x: (-.1, .1), y: (pi-1, pi+1)}
+    >>> series_approx2 = SeriesApprox(bounds, reltol=1e-2)
+    >>> series_approx3 = SeriesApprox(bounds, reltol=1e-3)
+    >>> series_approx8 = SeriesApprox(bounds, reltol=1e-8)
+    >>> expr = sin(x)*sin(y)
+    >>> optimize(expr, [series_approx2])
+    x*(-y + (y - pi)**3/6 + pi)
+    >>> optimize(expr, [series_approx3])
+    (-x**3/6 + x)*sin(y)
+    >>> optimize(expr, [series_approx8])
+    sin(x)*sin(y)
+
+    """
+    def __init__(self, bounds, reltol, max_order=4, n_point_checks=4, **kwargs):
+        super().__init__(**kwargs)
+        self.bounds = bounds
+        self.reltol = reltol
+        self.max_order = max_order
+        if n_point_checks % 2 == 1:
+            raise ValueError("Checking the solution at expansion point is not helpful")
+        self.n_point_checks = n_point_checks
+        self._prec = math.ceil(-math.log10(self.reltol))
+
+    def __call__(self, expr):
+        return expr.factor().replace(self.query, lambda arg: self.value(arg))
+
+    def query(self, expr):
+        return (expr.is_Function and not isinstance(expr, UndefinedFunction)
+                and len(expr.args) == 1)
+
+    def value(self, fexpr):
+        free_symbols = fexpr.free_symbols
+        if len(free_symbols) != 1:
+            return fexpr
+        symb, = free_symbols
+        if symb not in self.bounds:
+            return fexpr
+        lo, hi = self.bounds[symb]
+        x0 = (lo + hi)/2
+        cheapest = None
+        for n in range(self.max_order+1, 0, -1):
+            fseri = fexpr.series(symb, x0=x0, n=n).removeO()
+            n_ok = True
+            for idx in range(self.n_point_checks):
+                x = lo + idx*(hi - lo)/(self.n_point_checks - 1)
+                val = fseri.xreplace({symb: x})
+                ref = fexpr.xreplace({symb: x})
+                if abs((1 - val/ref).evalf(self._prec)) > self.reltol:
+                    n_ok = False
+                    break
+
+            if n_ok:
+                cheapest = fseri
+            else:
+                break
+
+        if cheapest is None:
+            return fexpr
+        else:
+            return cheapest

.venv/lib/python3.12/site-packages/sympy/codegen/ast.py

@@ -0,0 +1,1906 @@
+"""
+Types used to represent a full function/module as an Abstract Syntax Tree.
+
+Most types are small, and are merely used as tokens in the AST. A tree diagram
+has been included below to illustrate the relationships between the AST types.
+
+
+AST Type Tree
+-------------
+::
+
+  *Basic*
+       |
+       |
+   CodegenAST
+       |
+       |--->AssignmentBase
+       |             |--->Assignment
+       |             |--->AugmentedAssignment
+       |                                    |--->AddAugmentedAssignment
+       |                                    |--->SubAugmentedAssignment
+       |                                    |--->MulAugmentedAssignment
+       |                                    |--->DivAugmentedAssignment
+       |                                    |--->ModAugmentedAssignment
+       |
+       |--->CodeBlock
+       |
+       |
+       |--->Token
+                |--->Attribute
+                |--->For
+                |--->String
+                |       |--->QuotedString
+                |       |--->Comment
+                |--->Type
+                |       |--->IntBaseType
+                |       |              |--->_SizedIntType
+                |       |                               |--->SignedIntType
+                |       |                               |--->UnsignedIntType
+                |       |--->FloatBaseType
+                |                        |--->FloatType
+                |                        |--->ComplexBaseType
+                |                                           |--->ComplexType
+                |--->Node
+                |       |--->Variable
+                |       |           |---> Pointer
+                |       |--->FunctionPrototype
+                |                            |--->FunctionDefinition
+                |--->Element
+                |--->Declaration
+                |--->While
+                |--->Scope
+                |--->Stream
+                |--->Print
+                |--->FunctionCall
+                |--->BreakToken
+                |--->ContinueToken
+                |--->NoneToken
+                |--->Return
+
+
+Predefined types
+----------------
+
+A number of ``Type`` instances are provided in the ``sympy.codegen.ast`` module
+for convenience. Perhaps the two most common ones for code-generation (of numeric
+codes) are ``float32`` and ``float64`` (known as single and double precision respectively).
+There are also precision generic versions of Types (for which the codeprinters selects the
+underlying data type at time of printing): ``real``, ``integer``, ``complex_``, ``bool_``.
+
+The other ``Type`` instances defined are:
+
+- ``intc``: Integer type used by C's "int".
+- ``intp``: Integer type used by C's "unsigned".
+- ``int8``, ``int16``, ``int32``, ``int64``: n-bit integers.
+- ``uint8``, ``uint16``, ``uint32``, ``uint64``: n-bit unsigned integers.
+- ``float80``: known as "extended precision" on modern x86/amd64 hardware.
+- ``complex64``: Complex number represented by two ``float32`` numbers
+- ``complex128``: Complex number represented by two ``float64`` numbers
+
+Using the nodes
+---------------
+
+It is possible to construct simple algorithms using the AST nodes. Let's construct a loop applying
+Newton's method::
+
+    >>> from sympy import symbols, cos
+    >>> from sympy.codegen.ast import While, Assignment, aug_assign, Print, QuotedString
+    >>> t, dx, x = symbols('tol delta val')
+    >>> expr = cos(x) - x**3
+    >>> whl = While(abs(dx) > t, [
+    ...     Assignment(dx, -expr/expr.diff(x)),
+    ...     aug_assign(x, '+', dx),
+    ...     Print([x])
+    ... ])
+    >>> from sympy import pycode
+    >>> py_str = pycode(whl)
+    >>> print(py_str)
+    while (abs(delta) > tol):
+        delta = (val**3 - math.cos(val))/(-3*val**2 - math.sin(val))
+        val += delta
+        print(val)
+    >>> import math
+    >>> tol, val, delta = 1e-5, 0.5, float('inf')
+    >>> exec(py_str)
+    1.1121416371
+    0.909672693737
+    0.867263818209
+    0.865477135298
+    0.865474033111
+    >>> print('%3.1g' % (math.cos(val) - val**3))
+    -3e-11
+
+If we want to generate Fortran code for the same while loop we simple call ``fcode``::
+
+    >>> from sympy import fcode
+    >>> print(fcode(whl, standard=2003, source_format='free'))
+    do while (abs(delta) > tol)
+       delta = (val**3 - cos(val))/(-3*val**2 - sin(val))
+       val = val + delta
+       print *, val
+    end do
+
+There is a function constructing a loop (or a complete function) like this in
+:mod:`sympy.codegen.algorithms`.
+
+"""
+
+from __future__ import annotations
+from typing import Any
+
+from collections import defaultdict
+
+from sympy.core.relational import (Ge, Gt, Le, Lt)
+from sympy.core import Symbol, Tuple, Dummy
+from sympy.core.basic import Basic
+from sympy.core.expr import Expr, Atom
+from sympy.core.numbers import Float, Integer, oo
+from sympy.core.sympify import _sympify, sympify, SympifyError
+from sympy.utilities.iterables import (iterable, topological_sort,
+                                       numbered_symbols, filter_symbols)
+
+
+def _mk_Tuple(args):
+    """
+    Create a SymPy Tuple object from an iterable, converting Python strings to
+    AST strings.
+
+    Parameters
+    ==========
+
+    args: iterable
+        Arguments to :class:`sympy.Tuple`.
+
+    Returns
+    =======
+
+    sympy.Tuple
+    """
+    args = [String(arg) if isinstance(arg, str) else arg for arg in args]
+    return Tuple(*args)
+
+
+class CodegenAST(Basic):
+    __slots__ = ()
+
+
+class Token(CodegenAST):
+    """ Base class for the AST types.
+
+    Explanation
+    ===========
+
+    Defining fields are set in ``_fields``. Attributes (defined in _fields)
+    are only allowed to contain instances of Basic (unless atomic, see
+    ``String``). The arguments to ``__new__()`` correspond to the attributes in
+    the order defined in ``_fields`. The ``defaults`` class attribute is a
+    dictionary mapping attribute names to their default values.
+
+    Subclasses should not need to override the ``__new__()`` method. They may
+    define a class or static method named ``_construct_<attr>`` for each
+    attribute to process the value passed to ``__new__()``. Attributes listed
+    in the class attribute ``not_in_args`` are not passed to :class:`~.Basic`.
+    """
+
+    __slots__: tuple[str, ...] = ()
+    _fields = __slots__
+    defaults: dict[str, Any] = {}
+    not_in_args: list[str] = []
+    indented_args = ['body']
+
+    @property
+    def is_Atom(self):
+        return len(self._fields) == 0
+
+    @classmethod
+    def _get_constructor(cls, attr):
+        """ Get the constructor function for an attribute by name. """
+        return getattr(cls, '_construct_%s' % attr, lambda x: x)
+
+    @classmethod
+    def _construct(cls, attr, arg):
+        """ Construct an attribute value from argument passed to ``__new__()``. """
+        # arg may be ``NoneToken()``, so comparison is done using == instead of ``is`` operator
+        if arg == None:
+            return cls.defaults.get(attr, none)
+        else:
+            if isinstance(arg, Dummy):  # SymPy's replace uses Dummy instances
+                return arg
+            else:
+                return cls._get_constructor(attr)(arg)
+
+    def __new__(cls, *args, **kwargs):
+        # Pass through existing instances when given as sole argument
+        if len(args) == 1 and not kwargs and isinstance(args[0], cls):
+            return args[0]
+
+        if len(args) > len(cls._fields):
+            raise ValueError("Too many arguments (%d), expected at most %d" % (len(args), len(cls._fields)))
+
+        attrvals = []
+
+        # Process positional arguments
+        for attrname, argval in zip(cls._fields, args):
+            if attrname in kwargs:
+                raise TypeError('Got multiple values for attribute %r' % attrname)
+
+            attrvals.append(cls._construct(attrname, argval))
+
+        # Process keyword arguments
+        for attrname in cls._fields[len(args):]:
+            if attrname in kwargs:
+                argval = kwargs.pop(attrname)
+
+            elif attrname in cls.defaults:
+                argval = cls.defaults[attrname]
+
+            else:
+                raise TypeError('No value for %r given and attribute has no default' % attrname)
+
+            attrvals.append(cls._construct(attrname, argval))
+
+        if kwargs:
+            raise ValueError("Unknown keyword arguments: %s" % ' '.join(kwargs))
+
+        # Parent constructor
+        basic_args = [
+            val for attr, val in zip(cls._fields, attrvals)
+            if attr not in cls.not_in_args
+        ]
+        obj = CodegenAST.__new__(cls, *basic_args)
+
+        # Set attributes
+        for attr, arg in zip(cls._fields, attrvals):
+            setattr(obj, attr, arg)
+
+        return obj
+
+    def __eq__(self, other):
+        if not isinstance(other, self.__class__):
+            return False
+        for attr in self._fields:
+            if getattr(self, attr) != getattr(other, attr):
+                return False
+        return True
+
+    def _hashable_content(self):
+        return tuple([getattr(self, attr) for attr in self._fields])
+
+    def __hash__(self):
+        return super().__hash__()
+
+    def _joiner(self, k, indent_level):
+        return (',\n' + ' '*indent_level) if k in self.indented_args else ', '
+
+    def _indented(self, printer, k, v, *args, **kwargs):
+        il = printer._context['indent_level']
+        def _print(arg):
+            if isinstance(arg, Token):
+                return printer._print(arg, *args, joiner=self._joiner(k, il), **kwargs)
+            else:
+                return printer._print(arg, *args, **kwargs)
+
+        if isinstance(v, Tuple):
+            joined = self._joiner(k, il).join([_print(arg) for arg in v.args])
+            if k in self.indented_args:
+                return '(\n' + ' '*il + joined + ',\n' + ' '*(il - 4) + ')'
+            else:
+                return ('({0},)' if len(v.args) == 1 else '({0})').format(joined)
+        else:
+            return _print(v)
+
+    def _sympyrepr(self, printer, *args, joiner=', ', **kwargs):
+        from sympy.printing.printer import printer_context
+        exclude = kwargs.get('exclude', ())
+        values = [getattr(self, k) for k in self._fields]
+        indent_level = printer._context.get('indent_level', 0)
+
+        arg_reprs = []
+
+        for i, (attr, value) in enumerate(zip(self._fields, values)):
+            if attr in exclude:
+                continue
+
+            # Skip attributes which have the default value
+            if attr in self.defaults and value == self.defaults[attr]:
+                continue
+
+            ilvl = indent_level + 4 if attr in self.indented_args else 0
+            with printer_context(printer, indent_level=ilvl):
+                indented = self._indented(printer, attr, value, *args, **kwargs)
+            arg_reprs.append(('{1}' if i == 0 else '{0}={1}').format(attr, indented.lstrip()))
+
+        return "{}({})".format(self.__class__.__name__, joiner.join(arg_reprs))
+
+    _sympystr = _sympyrepr
+
+    def __repr__(self):  # sympy.core.Basic.__repr__ uses sstr
+        from sympy.printing import srepr
+        return srepr(self)
+
+    def kwargs(self, exclude=(), apply=None):
+        """ Get instance's attributes as dict of keyword arguments.
+
+        Parameters
+        ==========
+
+        exclude : collection of str
+            Collection of keywords to exclude.
+
+        apply : callable, optional
+            Function to apply to all values.
+        """
+        kwargs = {k: getattr(self, k) for k in self._fields if k not in exclude}
+        if apply is not None:
+            return {k: apply(v) for k, v in kwargs.items()}
+        else:
+            return kwargs
+
+class BreakToken(Token):
+    """ Represents 'break' in C/Python ('exit' in Fortran).
+
+    Use the premade instance ``break_`` or instantiate manually.
+
+    Examples
+    ========
+
+    >>> from sympy import ccode, fcode
+    >>> from sympy.codegen.ast import break_
+    >>> ccode(break_)
+    'break'
+    >>> fcode(break_, source_format='free')
+    'exit'
+    """
+
+break_ = BreakToken()
+
+
+class ContinueToken(Token):
+    """ Represents 'continue' in C/Python ('cycle' in Fortran)
+
+    Use the premade instance ``continue_`` or instantiate manually.
+
+    Examples
+    ========
+
+    >>> from sympy import ccode, fcode
+    >>> from sympy.codegen.ast import continue_
+    >>> ccode(continue_)
+    'continue'
+    >>> fcode(continue_, source_format='free')
+    'cycle'
+    """
+
+continue_ = ContinueToken()
+
+class NoneToken(Token):
+    """ The AST equivalence of Python's NoneType
+
+    The corresponding instance of Python's ``None`` is ``none``.
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import none, Variable
+    >>> from sympy import pycode
+    >>> print(pycode(Variable('x').as_Declaration(value=none)))
+    x = None
+
+    """
+    def __eq__(self, other):
+        return other is None or isinstance(other, NoneToken)
+
+    def _hashable_content(self):
+        return ()
+
+    def __hash__(self):
+        return super().__hash__()
+
+
+none = NoneToken()
+
+
+class AssignmentBase(CodegenAST):
+    """ Abstract base class for Assignment and AugmentedAssignment.
+
+    Attributes:
+    ===========
+
+    op : str
+        Symbol for assignment operator, e.g. "=", "+=", etc.
+    """
+
+    def __new__(cls, lhs, rhs):
+        lhs = _sympify(lhs)
+        rhs = _sympify(rhs)
+
+        cls._check_args(lhs, rhs)
+
+        return super().__new__(cls, lhs, rhs)
+
+    @property
+    def lhs(self):
+        return self.args[0]
+
+    @property
+    def rhs(self):
+        return self.args[1]
+
+    @classmethod
+    def _check_args(cls, lhs, rhs):
+        """ Check arguments to __new__ and raise exception if any problems found.
+
+        Derived classes may wish to override this.
+        """
+        from sympy.matrices.expressions.matexpr import (
+            MatrixElement, MatrixSymbol)
+        from sympy.tensor.indexed import Indexed
+        from sympy.tensor.array.expressions import ArrayElement
+
+        # Tuple of things that can be on the lhs of an assignment
+        assignable = (Symbol, MatrixSymbol, MatrixElement, Indexed, Element, Variable,
+                ArrayElement)
+        if not isinstance(lhs, assignable):
+            raise TypeError("Cannot assign to lhs of type %s." % type(lhs))
+
+        # Indexed types implement shape, but don't define it until later. This
+        # causes issues in assignment validation. For now, matrices are defined
+        # as anything with a shape that is not an Indexed
+        lhs_is_mat = hasattr(lhs, 'shape') and not isinstance(lhs, Indexed)
+        rhs_is_mat = hasattr(rhs, 'shape') and not isinstance(rhs, Indexed)
+
+        # If lhs and rhs have same structure, then this assignment is ok
+        if lhs_is_mat:
+            if not rhs_is_mat:
+                raise ValueError("Cannot assign a scalar to a matrix.")
+            elif lhs.shape != rhs.shape:
+                raise ValueError("Dimensions of lhs and rhs do not align.")
+        elif rhs_is_mat and not lhs_is_mat:
+            raise ValueError("Cannot assign a matrix to a scalar.")
+
+
+class Assignment(AssignmentBase):
+    """
+    Represents variable assignment for code generation.
+
+    Parameters
+    ==========
+
+    lhs : Expr
+        SymPy object representing the lhs of the expression. These should be
+        singular objects, such as one would use in writing code. Notable types
+        include Symbol, MatrixSymbol, MatrixElement, and Indexed. Types that
+        subclass these types are also supported.
+
+    rhs : Expr
+        SymPy object representing the rhs of the expression. This can be any
+        type, provided its shape corresponds to that of the lhs. For example,
+        a Matrix type can be assigned to MatrixSymbol, but not to Symbol, as
+        the dimensions will not align.
+
+    Examples
+    ========
+
+    >>> from sympy import symbols, MatrixSymbol, Matrix
+    >>> from sympy.codegen.ast import Assignment
+    >>> x, y, z = symbols('x, y, z')
+    >>> Assignment(x, y)
+    Assignment(x, y)
+    >>> Assignment(x, 0)
+    Assignment(x, 0)
+    >>> A = MatrixSymbol('A', 1, 3)
+    >>> mat = Matrix([x, y, z]).T
+    >>> Assignment(A, mat)
+    Assignment(A, Matrix([[x, y, z]]))
+    >>> Assignment(A[0, 1], x)
+    Assignment(A[0, 1], x)
+    """
+
+    op = ':='
+
+
+class AugmentedAssignment(AssignmentBase):
+    """
+    Base class for augmented assignments.
+
+    Attributes:
+    ===========
+
+    binop : str
+       Symbol for binary operation being applied in the assignment, such as "+",
+       "*", etc.
+    """
+    binop: str | None
+
+    @property
+    def op(self):
+        return self.binop + '='
+
+
+class AddAugmentedAssignment(AugmentedAssignment):
+    binop = '+'
+
+
+class SubAugmentedAssignment(AugmentedAssignment):
+    binop = '-'
+
+
+class MulAugmentedAssignment(AugmentedAssignment):
+    binop = '*'
+
+
+class DivAugmentedAssignment(AugmentedAssignment):
+    binop = '/'
+
+
+class ModAugmentedAssignment(AugmentedAssignment):
+    binop = '%'
+
+
+# Mapping from binary op strings to AugmentedAssignment subclasses
+augassign_classes = {
+    cls.binop: cls for cls in [
+        AddAugmentedAssignment, SubAugmentedAssignment, MulAugmentedAssignment,
+        DivAugmentedAssignment, ModAugmentedAssignment
+    ]
+}
+
+
+def aug_assign(lhs, op, rhs):
+    """
+    Create 'lhs op= rhs'.
+
+    Explanation
+    ===========
+
+    Represents augmented variable assignment for code generation. This is a
+    convenience function. You can also use the AugmentedAssignment classes
+    directly, like AddAugmentedAssignment(x, y).
+
+    Parameters
+    ==========
+
+    lhs : Expr
+        SymPy object representing the lhs of the expression. These should be
+        singular objects, such as one would use in writing code. Notable types
+        include Symbol, MatrixSymbol, MatrixElement, and Indexed. Types that
+        subclass these types are also supported.
+
+    op : str
+        Operator (+, -, /, \\*, %).
+
+    rhs : Expr
+        SymPy object representing the rhs of the expression. This can be any
+        type, provided its shape corresponds to that of the lhs. For example,
+        a Matrix type can be assigned to MatrixSymbol, but not to Symbol, as
+        the dimensions will not align.
+
+    Examples
+    ========
+
+    >>> from sympy import symbols
+    >>> from sympy.codegen.ast import aug_assign
+    >>> x, y = symbols('x, y')
+    >>> aug_assign(x, '+', y)
+    AddAugmentedAssignment(x, y)
+    """
+    if op not in augassign_classes:
+        raise ValueError("Unrecognized operator %s" % op)
+    return augassign_classes[op](lhs, rhs)
+
+
+class CodeBlock(CodegenAST):
+    """
+    Represents a block of code.
+
+    Explanation
+    ===========
+
+    For now only assignments are supported. This restriction will be lifted in
+    the future.
+
+    Useful attributes on this object are:
+
+    ``left_hand_sides``:
+        Tuple of left-hand sides of assignments, in order.
+    ``left_hand_sides``:
+        Tuple of right-hand sides of assignments, in order.
+    ``free_symbols``: Free symbols of the expressions in the right-hand sides
+        which do not appear in the left-hand side of an assignment.
+
+    Useful methods on this object are:
+
+    ``topological_sort``:
+        Class method. Return a CodeBlock with assignments
+        sorted so that variables are assigned before they
+        are used.
+    ``cse``:
+        Return a new CodeBlock with common subexpressions eliminated and
+        pulled out as assignments.
+
+    Examples
+    ========
+
+    >>> from sympy import symbols, ccode
+    >>> from sympy.codegen.ast import CodeBlock, Assignment
+    >>> x, y = symbols('x y')
+    >>> c = CodeBlock(Assignment(x, 1), Assignment(y, x + 1))
+    >>> print(ccode(c))
+    x = 1;
+    y = x + 1;
+
+    """
+    def __new__(cls, *args):
+        left_hand_sides = []
+        right_hand_sides = []
+        for i in args:
+            if isinstance(i, Assignment):
+                lhs, rhs = i.args
+                left_hand_sides.append(lhs)
+                right_hand_sides.append(rhs)
+
+        obj = CodegenAST.__new__(cls, *args)
+
+        obj.left_hand_sides = Tuple(*left_hand_sides)
+        obj.right_hand_sides = Tuple(*right_hand_sides)
+        return obj
+
+    def __iter__(self):
+        return iter(self.args)
+
+    def _sympyrepr(self, printer, *args, **kwargs):
+        il = printer._context.get('indent_level', 0)
+        joiner = ',\n' + ' '*il
+        joined = joiner.join(map(printer._print, self.args))
+        return ('{}(\n'.format(' '*(il-4) + self.__class__.__name__,) +
+                ' '*il + joined + '\n' + ' '*(il - 4) + ')')
+
+    _sympystr = _sympyrepr
+
+    @property
+    def free_symbols(self):
+        return super().free_symbols - set(self.left_hand_sides)
+
+    @classmethod
+    def topological_sort(cls, assignments):
+        """
+        Return a CodeBlock with topologically sorted assignments so that
+        variables are assigned before they are used.
+
+        Examples
+        ========
+
+        The existing order of assignments is preserved as much as possible.
+
+        This function assumes that variables are assigned to only once.
+
+        This is a class constructor so that the default constructor for
+        CodeBlock can error when variables are used before they are assigned.
+
+        >>> from sympy import symbols
+        >>> from sympy.codegen.ast import CodeBlock, Assignment
+        >>> x, y, z = symbols('x y z')
+
+        >>> assignments = [
+        ...     Assignment(x, y + z),
+        ...     Assignment(y, z + 1),
+        ...     Assignment(z, 2),
+        ... ]
+        >>> CodeBlock.topological_sort(assignments)
+        CodeBlock(
+            Assignment(z, 2),
+            Assignment(y, z + 1),
+            Assignment(x, y + z)
+        )
+
+        """
+
+        if not all(isinstance(i, Assignment) for i in assignments):
+            # Will support more things later
+            raise NotImplementedError("CodeBlock.topological_sort only supports Assignments")
+
+        if any(isinstance(i, AugmentedAssignment) for i in assignments):
+            raise NotImplementedError("CodeBlock.topological_sort does not yet work with AugmentedAssignments")
+
+        # Create a graph where the nodes are assignments and there is a directed edge
+        # between nodes that use a variable and nodes that assign that
+        # variable, like
+
+        # [(x := 1, y := x + 1), (x := 1, z := y + z), (y := x + 1, z := y + z)]
+
+        # If we then topologically sort these nodes, they will be in
+        # assignment order, like
+
+        # x := 1
+        # y := x + 1
+        # z := y + z
+
+        # A = The nodes
+        #
+        # enumerate keeps nodes in the same order they are already in if
+        # possible. It will also allow us to handle duplicate assignments to
+        # the same variable when those are implemented.
+        A = list(enumerate(assignments))
+
+        # var_map = {variable: [nodes for which this variable is assigned to]}
+        # like {x: [(1, x := y + z), (4, x := 2 * w)], ...}
+        var_map = defaultdict(list)
+        for node in A:
+            i, a = node
+            var_map[a.lhs].append(node)
+
+        # E = Edges in the graph
+        E = []
+        for dst_node in A:
+            i, a = dst_node
+            for s in a.rhs.free_symbols:
+                for src_node in var_map[s]:
+                    E.append((src_node, dst_node))
+
+        ordered_assignments = topological_sort([A, E])
+
+        # De-enumerate the result
+        return cls(*[a for i, a in ordered_assignments])
+
+    def cse(self, symbols=None, optimizations=None, postprocess=None,
+        order='canonical'):
+        """
+        Return a new code block with common subexpressions eliminated.
+
+        Explanation
+        ===========
+
+        See the docstring of :func:`sympy.simplify.cse_main.cse` for more
+        information.
+
+        Examples
+        ========
+
+        >>> from sympy import symbols, sin
+        >>> from sympy.codegen.ast import CodeBlock, Assignment
+        >>> x, y, z = symbols('x y z')
+
+        >>> c = CodeBlock(
+        ...     Assignment(x, 1),
+        ...     Assignment(y, sin(x) + 1),
+        ...     Assignment(z, sin(x) - 1),
+        ... )
+        ...
+        >>> c.cse()
+        CodeBlock(
+            Assignment(x, 1),
+            Assignment(x0, sin(x)),
+            Assignment(y, x0 + 1),
+            Assignment(z, x0 - 1)
+        )
+
+        """
+        from sympy.simplify.cse_main import cse
+
+        # Check that the CodeBlock only contains assignments to unique variables
+        if not all(isinstance(i, Assignment) for i in self.args):
+            # Will support more things later
+            raise NotImplementedError("CodeBlock.cse only supports Assignments")
+
+        if any(isinstance(i, AugmentedAssignment) for i in self.args):
+            raise NotImplementedError("CodeBlock.cse does not yet work with AugmentedAssignments")
+
+        for i, lhs in enumerate(self.left_hand_sides):
+            if lhs in self.left_hand_sides[:i]:
+                raise NotImplementedError("Duplicate assignments to the same "
+                    "variable are not yet supported (%s)" % lhs)
+
+        # Ensure new symbols for subexpressions do not conflict with existing
+        existing_symbols = self.atoms(Symbol)
+        if symbols is None:
+            symbols = numbered_symbols()
+        symbols = filter_symbols(symbols, existing_symbols)
+
+        replacements, reduced_exprs = cse(list(self.right_hand_sides),
+            symbols=symbols, optimizations=optimizations, postprocess=postprocess,
+            order=order)
+
+        new_block = [Assignment(var, expr) for var, expr in
+            zip(self.left_hand_sides, reduced_exprs)]
+        new_assignments = [Assignment(var, expr) for var, expr in replacements]
+        return self.topological_sort(new_assignments + new_block)
+
+
+class For(Token):
+    """Represents a 'for-loop' in the code.
+
+    Expressions are of the form:
+        "for target in iter:
+            body..."
+
+    Parameters
+    ==========
+
+    target : symbol
+    iter : iterable
+    body : CodeBlock or iterable
+!        When passed an iterable it is used to instantiate a CodeBlock.
+
+    Examples
+    ========
+
+    >>> from sympy import symbols, Range
+    >>> from sympy.codegen.ast import aug_assign, For
+    >>> x, i, j, k = symbols('x i j k')
+    >>> for_i = For(i, Range(10), [aug_assign(x, '+', i*j*k)])
+    >>> for_i  # doctest: -NORMALIZE_WHITESPACE
+    For(i, iterable=Range(0, 10, 1), body=CodeBlock(
+        AddAugmentedAssignment(x, i*j*k)
+    ))
+    >>> for_ji = For(j, Range(7), [for_i])
+    >>> for_ji  # doctest: -NORMALIZE_WHITESPACE
+    For(j, iterable=Range(0, 7, 1), body=CodeBlock(
+        For(i, iterable=Range(0, 10, 1), body=CodeBlock(
+            AddAugmentedAssignment(x, i*j*k)
+        ))
+    ))
+    >>> for_kji =For(k, Range(5), [for_ji])
+    >>> for_kji  # doctest: -NORMALIZE_WHITESPACE
+    For(k, iterable=Range(0, 5, 1), body=CodeBlock(
+        For(j, iterable=Range(0, 7, 1), body=CodeBlock(
+            For(i, iterable=Range(0, 10, 1), body=CodeBlock(
+                AddAugmentedAssignment(x, i*j*k)
+            ))
+        ))
+    ))
+    """
+    __slots__ = _fields = ('target', 'iterable', 'body')
+    _construct_target = staticmethod(_sympify)
+
+    @classmethod
+    def _construct_body(cls, itr):
+        if isinstance(itr, CodeBlock):
+            return itr
+        else:
+            return CodeBlock(*itr)
+
+    @classmethod
+    def _construct_iterable(cls, itr):
+        if not iterable(itr):
+            raise TypeError("iterable must be an iterable")
+        if isinstance(itr, list):  # _sympify errors on lists because they are mutable
+            itr = tuple(itr)
+        return _sympify(itr)
+
+
+class String(Atom, Token):
+    """ SymPy object representing a string.
+
+    Atomic object which is not an expression (as opposed to Symbol).
+
+    Parameters
+    ==========
+
+    text : str
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import String
+    >>> f = String('foo')
+    >>> f
+    foo
+    >>> str(f)
+    'foo'
+    >>> f.text
+    'foo'
+    >>> print(repr(f))
+    String('foo')
+
+    """
+    __slots__ = _fields = ('text',)
+    not_in_args = ['text']
+    is_Atom = True
+
+    @classmethod
+    def _construct_text(cls, text):
+        if not isinstance(text, str):
+            raise TypeError("Argument text is not a string type.")
+        return text
+
+    def _sympystr(self, printer, *args, **kwargs):
+        return self.text
+
+    def kwargs(self, exclude = (), apply = None):
+        return {}
+
+    #to be removed when Atom is given a suitable func
+    @property
+    def func(self):
+        return lambda: self
+
+    def _latex(self, printer):
+        from sympy.printing.latex import latex_escape
+        return r'\texttt{{"{}"}}'.format(latex_escape(self.text))
+
+class QuotedString(String):
+    """ Represents a string which should be printed with quotes. """
+
+class Comment(String):
+    """ Represents a comment. """
+
+class Node(Token):
+    """ Subclass of Token, carrying the attribute 'attrs' (Tuple)
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import Node, value_const, pointer_const
+    >>> n1 = Node([value_const])
+    >>> n1.attr_params('value_const')  # get the parameters of attribute (by name)
+    ()
+    >>> from sympy.codegen.fnodes import dimension
+    >>> n2 = Node([value_const, dimension(5, 3)])
+    >>> n2.attr_params(value_const)  # get the parameters of attribute (by Attribute instance)
+    ()
+    >>> n2.attr_params('dimension')  # get the parameters of attribute (by name)
+    (5, 3)
+    >>> n2.attr_params(pointer_const) is None
+    True
+
+    """
+
+    __slots__: tuple[str, ...] = ('attrs',)
+    _fields = __slots__
+
+    defaults: dict[str, Any] = {'attrs': Tuple()}
+
+    _construct_attrs = staticmethod(_mk_Tuple)
+
+    def attr_params(self, looking_for):
+        """ Returns the parameters of the Attribute with name ``looking_for`` in self.attrs """
+        for attr in self.attrs:
+            if str(attr.name) == str(looking_for):
+                return attr.parameters
+
+
+class Type(Token):
+    """ Represents a type.
+
+    Explanation
+    ===========
+
+    The naming is a super-set of NumPy naming. Type has a classmethod
+    ``from_expr`` which offer type deduction. It also has a method
+    ``cast_check`` which casts the argument to its type, possibly raising an
+    exception if rounding error is not within tolerances, or if the value is not
+    representable by the underlying data type (e.g. unsigned integers).
+
+    Parameters
+    ==========
+
+    name : str
+        Name of the type, e.g. ``object``, ``int16``, ``float16`` (where the latter two
+        would use the ``Type`` sub-classes ``IntType`` and ``FloatType`` respectively).
+        If a ``Type`` instance is given, the said instance is returned.
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import Type
+    >>> t = Type.from_expr(42)
+    >>> t
+    integer
+    >>> print(repr(t))
+    IntBaseType(String('integer'))
+    >>> from sympy.codegen.ast import uint8
+    >>> uint8.cast_check(-1)   # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+      ...
+    ValueError: Minimum value for data type bigger than new value.
+    >>> from sympy.codegen.ast import float32
+    >>> v6 = 0.123456
+    >>> float32.cast_check(v6)
+    0.123456
+    >>> v10 = 12345.67894
+    >>> float32.cast_check(v10)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+      ...
+    ValueError: Casting gives a significantly different value.
+    >>> boost_mp50 = Type('boost::multiprecision::cpp_dec_float_50')
+    >>> from sympy import cxxcode
+    >>> from sympy.codegen.ast import Declaration, Variable
+    >>> cxxcode(Declaration(Variable('x', type=boost_mp50)))
+    'boost::multiprecision::cpp_dec_float_50 x'
+
+    References
+    ==========
+
+    .. [1] https://numpy.org/doc/stable/user/basics.types.html
+
+    """
+    __slots__: tuple[str, ...] = ('name',)
+    _fields = __slots__
+
+    _construct_name = String
+
+    def _sympystr(self, printer, *args, **kwargs):
+        return str(self.name)
+
+    @classmethod
+    def from_expr(cls, expr):
+        """ Deduces type from an expression or a ``Symbol``.
+
+        Parameters
+        ==========
+
+        expr : number or SymPy object
+            The type will be deduced from type or properties.
+
+        Examples
+        ========
+
+        >>> from sympy.codegen.ast import Type, integer, complex_
+        >>> Type.from_expr(2) == integer
+        True
+        >>> from sympy import Symbol
+        >>> Type.from_expr(Symbol('z', complex=True)) == complex_
+        True
+        >>> Type.from_expr(sum)  # doctest: +ELLIPSIS
+        Traceback (most recent call last):
+          ...
+        ValueError: Could not deduce type from expr.
+
+        Raises
+        ======
+
+        ValueError when type deduction fails.
+
+        """
+        if isinstance(expr, (float, Float)):
+            return real
+        if isinstance(expr, (int, Integer)) or getattr(expr, 'is_integer', False):
+            return integer
+        if getattr(expr, 'is_real', False):
+            return real
+        if isinstance(expr, complex) or getattr(expr, 'is_complex', False):
+            return complex_
+        if isinstance(expr, bool) or getattr(expr, 'is_Relational', False):
+            return bool_
+        else:
+            raise ValueError("Could not deduce type from expr.")
+
+    def _check(self, value):
+        pass
+
+    def cast_check(self, value, rtol=None, atol=0, precision_targets=None):
+        """ Casts a value to the data type of the instance.
+
+        Parameters
+        ==========
+
+        value : number
+        rtol : floating point number
+            Relative tolerance. (will be deduced if not given).
+        atol : floating point number
+            Absolute tolerance (in addition to ``rtol``).
+        type_aliases : dict
+            Maps substitutions for Type, e.g. {integer: int64, real: float32}
+
+        Examples
+        ========
+
+        >>> from sympy.codegen.ast import integer, float32, int8
+        >>> integer.cast_check(3.0) == 3
+        True
+        >>> float32.cast_check(1e-40)  # doctest: +ELLIPSIS
+        Traceback (most recent call last):
+          ...
+        ValueError: Minimum value for data type bigger than new value.
+        >>> int8.cast_check(256)  # doctest: +ELLIPSIS
+        Traceback (most recent call last):
+          ...
+        ValueError: Maximum value for data type smaller than new value.
+        >>> v10 = 12345.67894
+        >>> float32.cast_check(v10)  # doctest: +ELLIPSIS
+        Traceback (most recent call last):
+          ...
+        ValueError: Casting gives a significantly different value.
+        >>> from sympy.codegen.ast import float64
+        >>> float64.cast_check(v10)
+        12345.67894
+        >>> from sympy import Float
+        >>> v18 = Float('0.123456789012345646')
+        >>> float64.cast_check(v18)
+        Traceback (most recent call last):
+          ...
+        ValueError: Casting gives a significantly different value.
+        >>> from sympy.codegen.ast import float80
+        >>> float80.cast_check(v18)
+        0.123456789012345649
+
+        """
+        val = sympify(value)
+
+        ten = Integer(10)
+        exp10 = getattr(self, 'decimal_dig', None)
+
+        if rtol is None:
+            rtol = 1e-15 if exp10 is None else 2.0*ten**(-exp10)
+
+        def tol(num):
+            return atol + rtol*abs(num)
+
+        new_val = self.cast_nocheck(value)
+        self._check(new_val)
+
+        delta = new_val - val
+        if abs(delta) > tol(val):  # rounding, e.g. int(3.5) != 3.5
+            raise ValueError("Casting gives a significantly different value.")
+
+        return new_val
+
+    def _latex(self, printer):
+        from sympy.printing.latex import latex_escape
+        type_name = latex_escape(self.__class__.__name__)
+        name = latex_escape(self.name.text)
+        return r"\text{{{}}}\left(\texttt{{{}}}\right)".format(type_name, name)
+
+
+class IntBaseType(Type):
+    """ Integer base type, contains no size information. """
+    __slots__ = ()
+    cast_nocheck = lambda self, i: Integer(int(i))
+
+
+class _SizedIntType(IntBaseType):
+    __slots__ = ('nbits',)
+    _fields = Type._fields + __slots__
+
+    _construct_nbits = Integer
+
+    def _check(self, value):
+        if value < self.min:
+            raise ValueError("Value is too small: %d < %d" % (value, self.min))
+        if value > self.max:
+            raise ValueError("Value is too big: %d > %d" % (value, self.max))
+
+
+class SignedIntType(_SizedIntType):
+    """ Represents a signed integer type. """
+    __slots__ = ()
+    @property
+    def min(self):
+        return -2**(self.nbits-1)
+
+    @property
+    def max(self):
+        return 2**(self.nbits-1) - 1
+
+
+class UnsignedIntType(_SizedIntType):
+    """ Represents an unsigned integer type. """
+    __slots__ = ()
+    @property
+    def min(self):
+        return 0
+
+    @property
+    def max(self):
+        return 2**self.nbits - 1
+
+two = Integer(2)
+
+class FloatBaseType(Type):
+    """ Represents a floating point number type. """
+    __slots__ = ()
+    cast_nocheck = Float
+
+class FloatType(FloatBaseType):
+    """ Represents a floating point type with fixed bit width.
+
+    Base 2 & one sign bit is assumed.
+
+    Parameters
+    ==========
+
+    name : str
+        Name of the type.
+    nbits : integer
+        Number of bits used (storage).
+    nmant : integer
+        Number of bits used to represent the mantissa.
+    nexp : integer
+        Number of bits used to represent the mantissa.
+
+    Examples
+    ========
+
+    >>> from sympy import S
+    >>> from sympy.codegen.ast import FloatType
+    >>> half_precision = FloatType('f16', nbits=16, nmant=10, nexp=5)
+    >>> half_precision.max
+    65504
+    >>> half_precision.tiny == S(2)**-14
+    True
+    >>> half_precision.eps == S(2)**-10
+    True
+    >>> half_precision.dig == 3
+    True
+    >>> half_precision.decimal_dig == 5
+    True
+    >>> half_precision.cast_check(1.0)
+    1.0
+    >>> half_precision.cast_check(1e5)  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+      ...
+    ValueError: Maximum value for data type smaller than new value.
+    """
+
+    __slots__ = ('nbits', 'nmant', 'nexp',)
+    _fields = Type._fields + __slots__
+
+    _construct_nbits = _construct_nmant = _construct_nexp = Integer
+
+
+    @property
+    def max_exponent(self):
+        """ The largest positive number n, such that 2**(n - 1) is a representable finite value. """
+        # cf. C++'s ``std::numeric_limits::max_exponent``
+        return two**(self.nexp - 1)
+
+    @property
+    def min_exponent(self):
+        """ The lowest negative number n, such that 2**(n - 1) is a valid normalized number. """
+        # cf. C++'s ``std::numeric_limits::min_exponent``
+        return 3 - self.max_exponent
+
+    @property
+    def max(self):
+        """ Maximum value representable. """
+        return (1 - two**-(self.nmant+1))*two**self.max_exponent
+
+    @property
+    def tiny(self):
+        """ The minimum positive normalized value. """
+        # See C macros: FLT_MIN, DBL_MIN, LDBL_MIN
+        # or C++'s ``std::numeric_limits::min``
+        # or numpy.finfo(dtype).tiny
+        return two**(self.min_exponent - 1)
+
+
+    @property
+    def eps(self):
+        """ Difference between 1.0 and the next representable value. """
+        return two**(-self.nmant)
+
+    @property
+    def dig(self):
+        """ Number of decimal digits that are guaranteed to be preserved in text.
+
+        When converting text -> float -> text, you are guaranteed that at least ``dig``
+        number of digits are preserved with respect to rounding or overflow.
+        """
+        from sympy.functions import floor, log
+        return floor(self.nmant * log(2)/log(10))
+
+    @property
+    def decimal_dig(self):
+        """ Number of digits needed to store & load without loss.
+
+        Explanation
+        ===========
+
+        Number of decimal digits needed to guarantee that two consecutive conversions
+        (float -> text -> float) to be idempotent. This is useful when one do not want
+        to loose precision due to rounding errors when storing a floating point value
+        as text.
+        """
+        from sympy.functions import ceiling, log
+        return ceiling((self.nmant + 1) * log(2)/log(10) + 1)
+
+    def cast_nocheck(self, value):
+        """ Casts without checking if out of bounds or subnormal. """
+        if value == oo:  # float(oo) or oo
+            return float(oo)
+        elif value == -oo:  # float(-oo) or -oo
+            return float(-oo)
+        return Float(str(sympify(value).evalf(self.decimal_dig)), self.decimal_dig)
+
+    def _check(self, value):
+        if value < -self.max:
+            raise ValueError("Value is too small: %d < %d" % (value, -self.max))
+        if value > self.max:
+            raise ValueError("Value is too big: %d > %d" % (value, self.max))
+        if abs(value) < self.tiny:
+            raise ValueError("Smallest (absolute) value for data type bigger than new value.")
+
+class ComplexBaseType(FloatBaseType):
+
+    __slots__ = ()
+
+    def cast_nocheck(self, value):
+        """ Casts without checking if out of bounds or subnormal. """
+        from sympy.functions import re, im
+        return (
+            super().cast_nocheck(re(value)) +
+            super().cast_nocheck(im(value))*1j
+        )
+
+    def _check(self, value):
+        from sympy.functions import re, im
+        super()._check(re(value))
+        super()._check(im(value))
+
+
+class ComplexType(ComplexBaseType, FloatType):
+    """ Represents a complex floating point number. """
+    __slots__ = ()
+
+
+# NumPy types:
+intc = IntBaseType('intc')
+intp = IntBaseType('intp')
+int8 = SignedIntType('int8', 8)
+int16 = SignedIntType('int16', 16)
+int32 = SignedIntType('int32', 32)
+int64 = SignedIntType('int64', 64)
+uint8 = UnsignedIntType('uint8', 8)
+uint16 = UnsignedIntType('uint16', 16)
+uint32 = UnsignedIntType('uint32', 32)
+uint64 = UnsignedIntType('uint64', 64)
+float16 = FloatType('float16', 16, nexp=5, nmant=10)  # IEEE 754 binary16, Half precision
+float32 = FloatType('float32', 32, nexp=8, nmant=23)  # IEEE 754 binary32, Single precision
+float64 = FloatType('float64', 64, nexp=11, nmant=52)  # IEEE 754 binary64, Double precision
+float80 = FloatType('float80', 80, nexp=15, nmant=63)  # x86 extended precision (1 integer part bit), "long double"
+float128 = FloatType('float128', 128, nexp=15, nmant=112)  # IEEE 754 binary128, Quadruple precision
+float256 = FloatType('float256', 256, nexp=19, nmant=236)  # IEEE 754 binary256, Octuple precision
+
+complex64 = ComplexType('complex64', nbits=64, **float32.kwargs(exclude=('name', 'nbits')))
+complex128 = ComplexType('complex128', nbits=128, **float64.kwargs(exclude=('name', 'nbits')))
+
+# Generic types (precision may be chosen by code printers):
+untyped = Type('untyped')
+real = FloatBaseType('real')
+integer = IntBaseType('integer')
+complex_ = ComplexBaseType('complex')
+bool_ = Type('bool')
+
+
+class Attribute(Token):
+    """ Attribute (possibly parametrized)
+
+    For use with :class:`sympy.codegen.ast.Node` (which takes instances of
+    ``Attribute`` as ``attrs``).
+
+    Parameters
+    ==========
+
+    name : str
+    parameters : Tuple
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import Attribute
+    >>> volatile = Attribute('volatile')
+    >>> volatile
+    volatile
+    >>> print(repr(volatile))
+    Attribute(String('volatile'))
+    >>> a = Attribute('foo', [1, 2, 3])
+    >>> a
+    foo(1, 2, 3)
+    >>> a.parameters == (1, 2, 3)
+    True
+    """
+    __slots__ = _fields = ('name', 'parameters')
+    defaults = {'parameters': Tuple()}
+
+    _construct_name = String
+    _construct_parameters = staticmethod(_mk_Tuple)
+
+    def _sympystr(self, printer, *args, **kwargs):
+        result = str(self.name)
+        if self.parameters:
+            result += '(%s)' % ', '.join((printer._print(
+                arg, *args, **kwargs) for arg in self.parameters))
+        return result
+
+value_const = Attribute('value_const')
+pointer_const = Attribute('pointer_const')
+
+
+class Variable(Node):
+    """ Represents a variable.
+
+    Parameters
+    ==========
+
+    symbol : Symbol
+    type : Type (optional)
+        Type of the variable.
+    attrs : iterable of Attribute instances
+        Will be stored as a Tuple.
+
+    Examples
+    ========
+
+    >>> from sympy import Symbol
+    >>> from sympy.codegen.ast import Variable, float32, integer
+    >>> x = Symbol('x')
+    >>> v = Variable(x, type=float32)
+    >>> v.attrs
+    ()
+    >>> v == Variable('x')
+    False
+    >>> v == Variable('x', type=float32)
+    True
+    >>> v
+    Variable(x, type=float32)
+
+    One may also construct a ``Variable`` instance with the type deduced from
+    assumptions about the symbol using the ``deduced`` classmethod:
+
+    >>> i = Symbol('i', integer=True)
+    >>> v = Variable.deduced(i)
+    >>> v.type == integer
+    True
+    >>> v == Variable('i')
+    False
+    >>> from sympy.codegen.ast import value_const
+    >>> value_const in v.attrs
+    False
+    >>> w = Variable('w', attrs=[value_const])
+    >>> w
+    Variable(w, attrs=(value_const,))
+    >>> value_const in w.attrs
+    True
+    >>> w.as_Declaration(value=42)
+    Declaration(Variable(w, value=42, attrs=(value_const,)))
+
+    """
+
+    __slots__ = ('symbol', 'type', 'value')
+    _fields = __slots__ + Node._fields
+
+    defaults = Node.defaults.copy()
+    defaults.update({'type': untyped, 'value': none})
+
+    _construct_symbol = staticmethod(sympify)
+    _construct_value = staticmethod(sympify)
+
+    @classmethod
+    def deduced(cls, symbol, value=None, attrs=Tuple(), cast_check=True):
+        """ Alt. constructor with type deduction from ``Type.from_expr``.
+
+        Deduces type primarily from ``symbol``, secondarily from ``value``.
+
+        Parameters
+        ==========
+
+        symbol : Symbol
+        value : expr
+            (optional) value of the variable.
+        attrs : iterable of Attribute instances
+        cast_check : bool
+            Whether to apply ``Type.cast_check`` on ``value``.
+
+        Examples
+        ========
+
+        >>> from sympy import Symbol
+        >>> from sympy.codegen.ast import Variable, complex_
+        >>> n = Symbol('n', integer=True)
+        >>> str(Variable.deduced(n).type)
+        'integer'
+        >>> x = Symbol('x', real=True)
+        >>> v = Variable.deduced(x)
+        >>> v.type
+        real
+        >>> z = Symbol('z', complex=True)
+        >>> Variable.deduced(z).type == complex_
+        True
+
+        """
+        if isinstance(symbol, Variable):
+            return symbol
+
+        try:
+            type_ = Type.from_expr(symbol)
+        except ValueError:
+            type_ = Type.from_expr(value)
+
+        if value is not None and cast_check:
+            value = type_.cast_check(value)
+        return cls(symbol, type=type_, value=value, attrs=attrs)
+
+    def as_Declaration(self, **kwargs):
+        """ Convenience method for creating a Declaration instance.
+
+        Explanation
+        ===========
+
+        If the variable of the Declaration need to wrap a modified
+        variable keyword arguments may be passed (overriding e.g.
+        the ``value`` of the Variable instance).
+
+        Examples
+        ========
+
+        >>> from sympy.codegen.ast import Variable, NoneToken
+        >>> x = Variable('x')
+        >>> decl1 = x.as_Declaration()
+        >>> # value is special NoneToken() which must be tested with == operator
+        >>> decl1.variable.value is None  # won't work
+        False
+        >>> decl1.variable.value == None  # not PEP-8 compliant
+        True
+        >>> decl1.variable.value == NoneToken()  # OK
+        True
+        >>> decl2 = x.as_Declaration(value=42.0)
+        >>> decl2.variable.value == 42.0
+        True
+
+        """
+        kw = self.kwargs()
+        kw.update(kwargs)
+        return Declaration(self.func(**kw))
+
+    def _relation(self, rhs, op):
+        try:
+            rhs = _sympify(rhs)
+        except SympifyError:
+            raise TypeError("Invalid comparison %s < %s" % (self, rhs))
+        return op(self, rhs, evaluate=False)
+
+    __lt__ = lambda self, other: self._relation(other, Lt)
+    __le__ = lambda self, other: self._relation(other, Le)
+    __ge__ = lambda self, other: self._relation(other, Ge)
+    __gt__ = lambda self, other: self._relation(other, Gt)
+
+class Pointer(Variable):
+    """ Represents a pointer. See ``Variable``.
+
+    Examples
+    ========
+
+    Can create instances of ``Element``:
+
+    >>> from sympy import Symbol
+    >>> from sympy.codegen.ast import Pointer
+    >>> i = Symbol('i', integer=True)
+    >>> p = Pointer('x')
+    >>> p[i+1]
+    Element(x, indices=(i + 1,))
+
+    """
+    __slots__ = ()
+
+    def __getitem__(self, key):
+        try:
+            return Element(self.symbol, key)
+        except TypeError:
+            return Element(self.symbol, (key,))
+
+
+class Element(Token):
+    """ Element in (a possibly N-dimensional) array.
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import Element
+    >>> elem = Element('x', 'ijk')
+    >>> elem.symbol.name == 'x'
+    True
+    >>> elem.indices
+    (i, j, k)
+    >>> from sympy import ccode
+    >>> ccode(elem)
+    'x[i][j][k]'
+    >>> ccode(Element('x', 'ijk', strides='lmn', offset='o'))
+    'x[i*l + j*m + k*n + o]'
+
+    """
+    __slots__ = _fields = ('symbol', 'indices', 'strides', 'offset')
+    defaults = {'strides': none, 'offset': none}
+    _construct_symbol = staticmethod(sympify)
+    _construct_indices = staticmethod(lambda arg: Tuple(*arg))
+    _construct_strides = staticmethod(lambda arg: Tuple(*arg))
+    _construct_offset = staticmethod(sympify)
+
+
+class Declaration(Token):
+    """ Represents a variable declaration
+
+    Parameters
+    ==========
+
+    variable : Variable
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import Declaration, NoneToken, untyped
+    >>> z = Declaration('z')
+    >>> z.variable.type == untyped
+    True
+    >>> # value is special NoneToken() which must be tested with == operator
+    >>> z.variable.value is None  # won't work
+    False
+    >>> z.variable.value == None  # not PEP-8 compliant
+    True
+    >>> z.variable.value == NoneToken()  # OK
+    True
+    """
+    __slots__ = _fields = ('variable',)
+    _construct_variable = Variable
+
+
+class While(Token):
+    """ Represents a 'for-loop' in the code.
+
+    Expressions are of the form:
+        "while condition:
+             body..."
+
+    Parameters
+    ==========
+
+    condition : expression convertible to Boolean
+    body : CodeBlock or iterable
+        When passed an iterable it is used to instantiate a CodeBlock.
+
+    Examples
+    ========
+
+    >>> from sympy import symbols, Gt, Abs
+    >>> from sympy.codegen import aug_assign, Assignment, While
+    >>> x, dx = symbols('x dx')
+    >>> expr = 1 - x**2
+    >>> whl = While(Gt(Abs(dx), 1e-9), [
+    ...     Assignment(dx, -expr/expr.diff(x)),
+    ...     aug_assign(x, '+', dx)
+    ... ])
+
+    """
+    __slots__ = _fields = ('condition', 'body')
+    _construct_condition = staticmethod(lambda cond: _sympify(cond))
+
+    @classmethod
+    def _construct_body(cls, itr):
+        if isinstance(itr, CodeBlock):
+            return itr
+        else:
+            return CodeBlock(*itr)
+
+
+class Scope(Token):
+    """ Represents a scope in the code.
+
+    Parameters
+    ==========
+
+    body : CodeBlock or iterable
+        When passed an iterable it is used to instantiate a CodeBlock.
+
+    """
+    __slots__ = _fields = ('body',)
+
+    @classmethod
+    def _construct_body(cls, itr):
+        if isinstance(itr, CodeBlock):
+            return itr
+        else:
+            return CodeBlock(*itr)
+
+
+class Stream(Token):
+    """ Represents a stream.
+
+    There are two predefined Stream instances ``stdout`` & ``stderr``.
+
+    Parameters
+    ==========
+
+    name : str
+
+    Examples
+    ========
+
+    >>> from sympy import pycode, Symbol
+    >>> from sympy.codegen.ast import Print, stderr, QuotedString
+    >>> print(pycode(Print(['x'], file=stderr)))
+    print(x, file=sys.stderr)
+    >>> x = Symbol('x')
+    >>> print(pycode(Print([QuotedString('x')], file=stderr)))  # print literally "x"
+    print("x", file=sys.stderr)
+
+    """
+    __slots__ = _fields = ('name',)
+    _construct_name = String
+
+stdout = Stream('stdout')
+stderr = Stream('stderr')
+
+
+class Print(Token):
+    r""" Represents print command in the code.
+
+    Parameters
+    ==========
+
+    formatstring : str
+    *args : Basic instances (or convertible to such through sympify)
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import Print
+    >>> from sympy import pycode
+    >>> print(pycode(Print('x y'.split(), "coordinate: %12.5g %12.5g\\n")))
+    print("coordinate: %12.5g %12.5g\n" % (x, y), end="")
+
+    """
+
+    __slots__ = _fields = ('print_args', 'format_string', 'file')
+    defaults = {'format_string': none, 'file': none}
+
+    _construct_print_args = staticmethod(_mk_Tuple)
+    _construct_format_string = QuotedString
+    _construct_file = Stream
+
+
+class FunctionPrototype(Node):
+    """ Represents a function prototype
+
+    Allows the user to generate forward declaration in e.g. C/C++.
+
+    Parameters
+    ==========
+
+    return_type : Type
+    name : str
+    parameters: iterable of Variable instances
+    attrs : iterable of Attribute instances
+
+    Examples
+    ========
+
+    >>> from sympy import ccode, symbols
+    >>> from sympy.codegen.ast import real, FunctionPrototype
+    >>> x, y = symbols('x y', real=True)
+    >>> fp = FunctionPrototype(real, 'foo', [x, y])
+    >>> ccode(fp)
+    'double foo(double x, double y)'
+
+    """
+
+    __slots__ = ('return_type', 'name', 'parameters')
+    _fields: tuple[str, ...] = __slots__ + Node._fields
+
+    _construct_return_type = Type
+    _construct_name = String
+
+    @staticmethod
+    def _construct_parameters(args):
+        def _var(arg):
+            if isinstance(arg, Declaration):
+                return arg.variable
+            elif isinstance(arg, Variable):
+                return arg
+            else:
+                return Variable.deduced(arg)
+        return Tuple(*map(_var, args))
+
+    @classmethod
+    def from_FunctionDefinition(cls, func_def):
+        if not isinstance(func_def, FunctionDefinition):
+            raise TypeError("func_def is not an instance of FunctionDefinition")
+        return cls(**func_def.kwargs(exclude=('body',)))
+
+
+class FunctionDefinition(FunctionPrototype):
+    """ Represents a function definition in the code.
+
+    Parameters
+    ==========
+
+    return_type : Type
+    name : str
+    parameters: iterable of Variable instances
+    body : CodeBlock or iterable
+    attrs : iterable of Attribute instances
+
+    Examples
+    ========
+
+    >>> from sympy import ccode, symbols
+    >>> from sympy.codegen.ast import real, FunctionPrototype
+    >>> x, y = symbols('x y', real=True)
+    >>> fp = FunctionPrototype(real, 'foo', [x, y])
+    >>> ccode(fp)
+    'double foo(double x, double y)'
+    >>> from sympy.codegen.ast import FunctionDefinition, Return
+    >>> body = [Return(x*y)]
+    >>> fd = FunctionDefinition.from_FunctionPrototype(fp, body)
+    >>> print(ccode(fd))
+    double foo(double x, double y){
+        return x*y;
+    }
+    """
+
+    __slots__ = ('body', )
+    _fields = FunctionPrototype._fields[:-1] + __slots__ + Node._fields
+
+    @classmethod
+    def _construct_body(cls, itr):
+        if isinstance(itr, CodeBlock):
+            return itr
+        else:
+            return CodeBlock(*itr)
+
+    @classmethod
+    def from_FunctionPrototype(cls, func_proto, body):
+        if not isinstance(func_proto, FunctionPrototype):
+            raise TypeError("func_proto is not an instance of FunctionPrototype")
+        return cls(body=body, **func_proto.kwargs())
+
+
+class Return(Token):
+    """ Represents a return command in the code.
+
+    Parameters
+    ==========
+
+    return : Basic
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import Return
+    >>> from sympy.printing.pycode import pycode
+    >>> from sympy import Symbol
+    >>> x = Symbol('x')
+    >>> print(pycode(Return(x)))
+    return x
+
+    """
+    __slots__ = _fields = ('return',)
+    _construct_return=staticmethod(_sympify)
+
+
+class FunctionCall(Token, Expr):
+    """ Represents a call to a function in the code.
+
+    Parameters
+    ==========
+
+    name : str
+    function_args : Tuple
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import FunctionCall
+    >>> from sympy import pycode
+    >>> fcall = FunctionCall('foo', 'bar baz'.split())
+    >>> print(pycode(fcall))
+    foo(bar, baz)
+
+    """
+    __slots__ = _fields = ('name', 'function_args')
+
+    _construct_name = String
+    _construct_function_args = staticmethod(lambda args: Tuple(*args))
+
+
+class Raise(Token):
+    """ Prints as 'raise ...' in Python, 'throw ...' in C++"""
+    __slots__ = _fields = ('exception',)
+
+
+class RuntimeError_(Token):
+    """ Represents 'std::runtime_error' in C++ and 'RuntimeError' in Python.
+
+    Note that the latter is uncommon, and you might want to use e.g. ValueError.
+    """
+    __slots__ = _fields = ('message',)
+    _construct_message = String

.venv/lib/python3.12/site-packages/sympy/codegen/cfunctions.py

@@ -0,0 +1,558 @@
+"""
+This module contains SymPy functions mathcin corresponding to special math functions in the
+C standard library (since C99, also available in C++11).
+
+The functions defined in this module allows the user to express functions such as ``expm1``
+as a SymPy function for symbolic manipulation.
+
+"""
+from sympy.core.function import ArgumentIndexError, Function
+from sympy.core.numbers import Rational
+from sympy.core.power import Pow
+from sympy.core.singleton import S
+from sympy.functions.elementary.exponential import exp, log
+from sympy.functions.elementary.miscellaneous import sqrt
+from sympy.logic.boolalg import BooleanFunction, true, false
+
+def _expm1(x):
+    return exp(x) - S.One
+
+
+class expm1(Function):
+    """
+    Represents the exponential function minus one.
+
+    Explanation
+    ===========
+
+    The benefit of using ``expm1(x)`` over ``exp(x) - 1``
+    is that the latter is prone to cancellation under finite precision
+    arithmetic when x is close to zero.
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cfunctions import expm1
+    >>> '%.0e' % expm1(1e-99).evalf()
+    '1e-99'
+    >>> from math import exp
+    >>> exp(1e-99) - 1
+    0.0
+    >>> expm1(x).diff(x)
+    exp(x)
+
+    See Also
+    ========
+
+    log1p
+    """
+    nargs = 1
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            return exp(*self.args)
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+    def _eval_expand_func(self, **hints):
+        return _expm1(*self.args)
+
+    def _eval_rewrite_as_exp(self, arg, **kwargs):
+        return exp(arg) - S.One
+
+    _eval_rewrite_as_tractable = _eval_rewrite_as_exp
+
+    @classmethod
+    def eval(cls, arg):
+        exp_arg = exp.eval(arg)
+        if exp_arg is not None:
+            return exp_arg - S.One
+
+    def _eval_is_real(self):
+        return self.args[0].is_real
+
+    def _eval_is_finite(self):
+        return self.args[0].is_finite
+
+
+def _log1p(x):
+    return log(x + S.One)
+
+
+class log1p(Function):
+    """
+    Represents the natural logarithm of a number plus one.
+
+    Explanation
+    ===========
+
+    The benefit of using ``log1p(x)`` over ``log(x + 1)``
+    is that the latter is prone to cancellation under finite precision
+    arithmetic when x is close to zero.
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cfunctions import log1p
+    >>> from sympy import expand_log
+    >>> '%.0e' % expand_log(log1p(1e-99)).evalf()
+    '1e-99'
+    >>> from math import log
+    >>> log(1 + 1e-99)
+    0.0
+    >>> log1p(x).diff(x)
+    1/(x + 1)
+
+    See Also
+    ========
+
+    expm1
+    """
+    nargs = 1
+
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            return S.One/(self.args[0] + S.One)
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+
+    def _eval_expand_func(self, **hints):
+        return _log1p(*self.args)
+
+    def _eval_rewrite_as_log(self, arg, **kwargs):
+        return _log1p(arg)
+
+    _eval_rewrite_as_tractable = _eval_rewrite_as_log
+
+    @classmethod
+    def eval(cls, arg):
+        if arg.is_Rational:
+            return log(arg + S.One)
+        elif not arg.is_Float:  # not safe to add 1 to Float
+            return log.eval(arg + S.One)
+        elif arg.is_number:
+            return log(Rational(arg) + S.One)
+
+    def _eval_is_real(self):
+        return (self.args[0] + S.One).is_nonnegative
+
+    def _eval_is_finite(self):
+        if (self.args[0] + S.One).is_zero:
+            return False
+        return self.args[0].is_finite
+
+    def _eval_is_positive(self):
+        return self.args[0].is_positive
+
+    def _eval_is_zero(self):
+        return self.args[0].is_zero
+
+    def _eval_is_nonnegative(self):
+        return self.args[0].is_nonnegative
+
+_Two = S(2)
+
+def _exp2(x):
+    return Pow(_Two, x)
+
+class exp2(Function):
+    """
+    Represents the exponential function with base two.
+
+    Explanation
+    ===========
+
+    The benefit of using ``exp2(x)`` over ``2**x``
+    is that the latter is not as efficient under finite precision
+    arithmetic.
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cfunctions import exp2
+    >>> exp2(2).evalf() == 4.0
+    True
+    >>> exp2(x).diff(x)
+    log(2)*exp2(x)
+
+    See Also
+    ========
+
+    log2
+    """
+    nargs = 1
+
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            return self*log(_Two)
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+    def _eval_rewrite_as_Pow(self, arg, **kwargs):
+        return _exp2(arg)
+
+    _eval_rewrite_as_tractable = _eval_rewrite_as_Pow
+
+    def _eval_expand_func(self, **hints):
+        return _exp2(*self.args)
+
+    @classmethod
+    def eval(cls, arg):
+        if arg.is_number:
+            return _exp2(arg)
+
+
+def _log2(x):
+    return log(x)/log(_Two)
+
+
+class log2(Function):
+    """
+    Represents the logarithm function with base two.
+
+    Explanation
+    ===========
+
+    The benefit of using ``log2(x)`` over ``log(x)/log(2)``
+    is that the latter is not as efficient under finite precision
+    arithmetic.
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cfunctions import log2
+    >>> log2(4).evalf() == 2.0
+    True
+    >>> log2(x).diff(x)
+    1/(x*log(2))
+
+    See Also
+    ========
+
+    exp2
+    log10
+    """
+    nargs = 1
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            return S.One/(log(_Two)*self.args[0])
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+
+    @classmethod
+    def eval(cls, arg):
+        if arg.is_number:
+            result = log.eval(arg, base=_Two)
+            if result.is_Atom:
+                return result
+        elif arg.is_Pow and arg.base == _Two:
+            return arg.exp
+
+    def _eval_evalf(self, *args, **kwargs):
+        return self.rewrite(log).evalf(*args, **kwargs)
+
+    def _eval_expand_func(self, **hints):
+        return _log2(*self.args)
+
+    def _eval_rewrite_as_log(self, arg, **kwargs):
+        return _log2(arg)
+
+    _eval_rewrite_as_tractable = _eval_rewrite_as_log
+
+
+def _fma(x, y, z):
+    return x*y + z
+
+
+class fma(Function):
+    """
+    Represents "fused multiply add".
+
+    Explanation
+    ===========
+
+    The benefit of using ``fma(x, y, z)`` over ``x*y + z``
+    is that, under finite precision arithmetic, the former is
+    supported by special instructions on some CPUs.
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x, y, z
+    >>> from sympy.codegen.cfunctions import fma
+    >>> fma(x, y, z).diff(x)
+    y
+
+    """
+    nargs = 3
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex in (1, 2):
+            return self.args[2 - argindex]
+        elif argindex == 3:
+            return S.One
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+
+    def _eval_expand_func(self, **hints):
+        return _fma(*self.args)
+
+    def _eval_rewrite_as_tractable(self, arg, limitvar=None, **kwargs):
+        return _fma(arg)
+
+
+_Ten = S(10)
+
+
+def _log10(x):
+    return log(x)/log(_Ten)
+
+
+class log10(Function):
+    """
+    Represents the logarithm function with base ten.
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cfunctions import log10
+    >>> log10(100).evalf() == 2.0
+    True
+    >>> log10(x).diff(x)
+    1/(x*log(10))
+
+    See Also
+    ========
+
+    log2
+    """
+    nargs = 1
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            return S.One/(log(_Ten)*self.args[0])
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+
+    @classmethod
+    def eval(cls, arg):
+        if arg.is_number:
+            result = log.eval(arg, base=_Ten)
+            if result.is_Atom:
+                return result
+        elif arg.is_Pow and arg.base == _Ten:
+            return arg.exp
+
+    def _eval_expand_func(self, **hints):
+        return _log10(*self.args)
+
+    def _eval_rewrite_as_log(self, arg, **kwargs):
+        return _log10(arg)
+
+    _eval_rewrite_as_tractable = _eval_rewrite_as_log
+
+
+def _Sqrt(x):
+    return Pow(x, S.Half)
+
+
+class Sqrt(Function):  # 'sqrt' already defined in sympy.functions.elementary.miscellaneous
+    """
+    Represents the square root function.
+
+    Explanation
+    ===========
+
+    The reason why one would use ``Sqrt(x)`` over ``sqrt(x)``
+    is that the latter is internally represented as ``Pow(x, S.Half)`` which
+    may not be what one wants when doing code-generation.
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cfunctions import Sqrt
+    >>> Sqrt(x)
+    Sqrt(x)
+    >>> Sqrt(x).diff(x)
+    1/(2*sqrt(x))
+
+    See Also
+    ========
+
+    Cbrt
+    """
+    nargs = 1
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            return Pow(self.args[0], Rational(-1, 2))/_Two
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+    def _eval_expand_func(self, **hints):
+        return _Sqrt(*self.args)
+
+    def _eval_rewrite_as_Pow(self, arg, **kwargs):
+        return _Sqrt(arg)
+
+    _eval_rewrite_as_tractable = _eval_rewrite_as_Pow
+
+
+def _Cbrt(x):
+    return Pow(x, Rational(1, 3))
+
+
+class Cbrt(Function):  # 'cbrt' already defined in sympy.functions.elementary.miscellaneous
+    """
+    Represents the cube root function.
+
+    Explanation
+    ===========
+
+    The reason why one would use ``Cbrt(x)`` over ``cbrt(x)``
+    is that the latter is internally represented as ``Pow(x, Rational(1, 3))`` which
+    may not be what one wants when doing code-generation.
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cfunctions import Cbrt
+    >>> Cbrt(x)
+    Cbrt(x)
+    >>> Cbrt(x).diff(x)
+    1/(3*x**(2/3))
+
+    See Also
+    ========
+
+    Sqrt
+    """
+    nargs = 1
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            return Pow(self.args[0], Rational(-_Two/3))/3
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+
+    def _eval_expand_func(self, **hints):
+        return _Cbrt(*self.args)
+
+    def _eval_rewrite_as_Pow(self, arg, **kwargs):
+        return _Cbrt(arg)
+
+    _eval_rewrite_as_tractable = _eval_rewrite_as_Pow
+
+
+def _hypot(x, y):
+    return sqrt(Pow(x, 2) + Pow(y, 2))
+
+
+class hypot(Function):
+    """
+    Represents the hypotenuse function.
+
+    Explanation
+    ===========
+
+    The hypotenuse function is provided by e.g. the math library
+    in the C99 standard, hence one may want to represent the function
+    symbolically when doing code-generation.
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x, y
+    >>> from sympy.codegen.cfunctions import hypot
+    >>> hypot(3, 4).evalf() == 5.0
+    True
+    >>> hypot(x, y)
+    hypot(x, y)
+    >>> hypot(x, y).diff(x)
+    x/hypot(x, y)
+
+    """
+    nargs = 2
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex in (1, 2):
+            return 2*self.args[argindex-1]/(_Two*self.func(*self.args))
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+
+    def _eval_expand_func(self, **hints):
+        return _hypot(*self.args)
+
+    def _eval_rewrite_as_Pow(self, arg, **kwargs):
+        return _hypot(arg)
+
+    _eval_rewrite_as_tractable = _eval_rewrite_as_Pow
+
+
+class isnan(BooleanFunction):
+    nargs = 1
+
+    @classmethod
+    def eval(cls, arg):
+        if arg is S.NaN:
+            return true
+        elif arg.is_number:
+            return false
+        else:
+            return None
+
+
+class isinf(BooleanFunction):
+    nargs = 1
+
+    @classmethod
+    def eval(cls, arg):
+        if arg.is_infinite:
+            return true
+        elif arg.is_finite:
+            return false
+        else:
+            return None

.venv/lib/python3.12/site-packages/sympy/codegen/cnodes.py

@@ -0,0 +1,156 @@
+"""
+AST nodes specific to the C family of languages
+"""
+
+from sympy.codegen.ast import (
+    Attribute, Declaration, Node, String, Token, Type, none,
+    FunctionCall, CodeBlock
+    )
+from sympy.core.basic import Basic
+from sympy.core.containers import Tuple
+from sympy.core.sympify import sympify
+
+void = Type('void')
+
+restrict = Attribute('restrict')  # guarantees no pointer aliasing
+volatile = Attribute('volatile')
+static = Attribute('static')
+
+
+def alignof(arg):
+    """ Generate of FunctionCall instance for calling 'alignof' """
+    return FunctionCall('alignof', [String(arg) if isinstance(arg, str) else arg])
+
+
+def sizeof(arg):
+    """ Generate of FunctionCall instance for calling 'sizeof'
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import real
+    >>> from sympy.codegen.cnodes import sizeof
+    >>> from sympy import ccode
+    >>> ccode(sizeof(real))
+    'sizeof(double)'
+    """
+    return FunctionCall('sizeof', [String(arg) if isinstance(arg, str) else arg])
+
+
+class CommaOperator(Basic):
+    """ Represents the comma operator in C """
+    def __new__(cls, *args):
+        return Basic.__new__(cls, *[sympify(arg) for arg in args])
+
+
+class Label(Node):
+    """ Label for use with e.g. goto statement.
+
+    Examples
+    ========
+
+    >>> from sympy import ccode, Symbol
+    >>> from sympy.codegen.cnodes import Label, PreIncrement
+    >>> print(ccode(Label('foo')))
+    foo:
+    >>> print(ccode(Label('bar', [PreIncrement(Symbol('a'))])))
+    bar:
+    ++(a);
+
+    """
+    __slots__ = _fields = ('name', 'body')
+    defaults = {'body': none}
+    _construct_name = String
+
+    @classmethod
+    def _construct_body(cls, itr):
+        if isinstance(itr, CodeBlock):
+            return itr
+        else:
+            return CodeBlock(*itr)
+
+
+class goto(Token):
+    """ Represents goto in C """
+    __slots__ = _fields = ('label',)
+    _construct_label = Label
+
+
+class PreDecrement(Basic):
+    """ Represents the pre-decrement operator
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cnodes import PreDecrement
+    >>> from sympy import ccode
+    >>> ccode(PreDecrement(x))
+    '--(x)'
+
+    """
+    nargs = 1
+
+
+class PostDecrement(Basic):
+    """ Represents the post-decrement operator
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cnodes import PostDecrement
+    >>> from sympy import ccode
+    >>> ccode(PostDecrement(x))
+    '(x)--'
+
+    """
+    nargs = 1
+
+
+class PreIncrement(Basic):
+    """ Represents the pre-increment operator
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cnodes import PreIncrement
+    >>> from sympy import ccode
+    >>> ccode(PreIncrement(x))
+    '++(x)'
+
+    """
+    nargs = 1
+
+
+class PostIncrement(Basic):
+    """ Represents the post-increment operator
+
+    Examples
+    ========
+
+    >>> from sympy.abc import x
+    >>> from sympy.codegen.cnodes import PostIncrement
+    >>> from sympy import ccode
+    >>> ccode(PostIncrement(x))
+    '(x)++'
+
+    """
+    nargs = 1
+
+
+class struct(Node):
+    """ Represents a struct in C """
+    __slots__ = _fields = ('name', 'declarations')
+    defaults = {'name': none}
+    _construct_name = String
+
+    @classmethod
+    def _construct_declarations(cls, args):
+        return Tuple(*[Declaration(arg) for arg in args])
+
+
+class union(struct):
+    """ Represents a union in C """
+    __slots__ = ()

.venv/lib/python3.12/site-packages/sympy/codegen/cutils.py

@@ -0,0 +1,8 @@
+from sympy.printing.c import C99CodePrinter
+
+def render_as_source_file(content, Printer=C99CodePrinter, settings=None):
+    """ Renders a C source file (with required #include statements) """
+    printer = Printer(settings or {})
+    code_str = printer.doprint(content)
+    includes = '\n'.join(['#include <%s>' % h for h in printer.headers])
+    return includes + '\n\n' + code_str

.venv/lib/python3.12/site-packages/sympy/codegen/cxxnodes.py

@@ -0,0 +1,14 @@
+"""
+AST nodes specific to C++.
+"""
+
+from sympy.codegen.ast import Attribute, String, Token, Type, none
+
+class using(Token):
+    """ Represents a 'using' statement in C++ """
+    __slots__ = _fields = ('type', 'alias')
+    defaults = {'alias': none}
+    _construct_type = Type
+    _construct_alias = String
+
+constexpr = Attribute('constexpr')

.venv/lib/python3.12/site-packages/sympy/codegen/fnodes.py

@@ -0,0 +1,658 @@
+"""
+AST nodes specific to Fortran.
+
+The functions defined in this module allows the user to express functions such as ``dsign``
+as a SymPy function for symbolic manipulation.
+"""
+
+from __future__ import annotations
+from sympy.codegen.ast import (
+    Attribute, CodeBlock, FunctionCall, Node, none, String,
+    Token, _mk_Tuple, Variable
+)
+from sympy.core.basic import Basic
+from sympy.core.containers import Tuple
+from sympy.core.expr import Expr
+from sympy.core.function import Function
+from sympy.core.numbers import Float, Integer
+from sympy.core.symbol import Str
+from sympy.core.sympify import sympify
+from sympy.logic import true, false
+from sympy.utilities.iterables import iterable
+
+
+
+pure = Attribute('pure')
+elemental = Attribute('elemental')  # (all elemental procedures are also pure)
+
+intent_in = Attribute('intent_in')
+intent_out = Attribute('intent_out')
+intent_inout = Attribute('intent_inout')
+
+allocatable = Attribute('allocatable')
+
+class Program(Token):
+    """ Represents a 'program' block in Fortran.
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.ast import Print
+    >>> from sympy.codegen.fnodes import Program
+    >>> prog = Program('myprogram', [Print([42])])
+    >>> from sympy import fcode
+    >>> print(fcode(prog, source_format='free'))
+    program myprogram
+        print *, 42
+    end program
+
+    """
+    __slots__ = _fields = ('name', 'body')
+    _construct_name = String
+    _construct_body = staticmethod(lambda body: CodeBlock(*body))
+
+
+class use_rename(Token):
+    """ Represents a renaming in a use statement in Fortran.
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.fnodes import use_rename, use
+    >>> from sympy import fcode
+    >>> ren = use_rename("thingy", "convolution2d")
+    >>> print(fcode(ren, source_format='free'))
+    thingy => convolution2d
+    >>> full = use('signallib', only=['snr', ren])
+    >>> print(fcode(full, source_format='free'))
+    use signallib, only: snr, thingy => convolution2d
+
+    """
+    __slots__ = _fields = ('local', 'original')
+    _construct_local = String
+    _construct_original = String
+
+def _name(arg):
+    if hasattr(arg, 'name'):
+        return arg.name
+    else:
+        return String(arg)
+
+class use(Token):
+    """ Represents a use statement in Fortran.
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.fnodes import use
+    >>> from sympy import fcode
+    >>> fcode(use('signallib'), source_format='free')
+    'use signallib'
+    >>> fcode(use('signallib', [('metric', 'snr')]), source_format='free')
+    'use signallib, metric => snr'
+    >>> fcode(use('signallib', only=['snr', 'convolution2d']), source_format='free')
+    'use signallib, only: snr, convolution2d'
+
+    """
+    __slots__ = _fields = ('namespace', 'rename', 'only')
+    defaults = {'rename': none, 'only': none}
+    _construct_namespace = staticmethod(_name)
+    _construct_rename = staticmethod(lambda args: Tuple(*[arg if isinstance(arg, use_rename) else use_rename(*arg) for arg in args]))
+    _construct_only = staticmethod(lambda args: Tuple(*[arg if isinstance(arg, use_rename) else _name(arg) for arg in args]))
+
+
+class Module(Token):
+    """ Represents a module in Fortran.
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.fnodes import Module
+    >>> from sympy import fcode
+    >>> print(fcode(Module('signallib', ['implicit none'], []), source_format='free'))
+    module signallib
+    implicit none
+    <BLANKLINE>
+    contains
+    <BLANKLINE>
+    <BLANKLINE>
+    end module
+
+    """
+    __slots__ = _fields = ('name', 'declarations', 'definitions')
+    defaults = {'declarations': Tuple()}
+    _construct_name = String
+
+    @classmethod
+    def _construct_declarations(cls, args):
+        args = [Str(arg) if isinstance(arg, str) else arg for arg in args]
+        return CodeBlock(*args)
+
+    _construct_definitions = staticmethod(lambda arg: CodeBlock(*arg))
+
+
+class Subroutine(Node):
+    """ Represents a subroutine in Fortran.
+
+    Examples
+    ========
+
+    >>> from sympy import fcode, symbols
+    >>> from sympy.codegen.ast import Print
+    >>> from sympy.codegen.fnodes import Subroutine
+    >>> x, y = symbols('x y', real=True)
+    >>> sub = Subroutine('mysub', [x, y], [Print([x**2 + y**2, x*y])])
+    >>> print(fcode(sub, source_format='free', standard=2003))
+    subroutine mysub(x, y)
+    real*8 :: x
+    real*8 :: y
+    print *, x**2 + y**2, x*y
+    end subroutine
+
+    """
+    __slots__ = ('name', 'parameters', 'body')
+    _fields = __slots__ + Node._fields
+    _construct_name = String
+    _construct_parameters = staticmethod(lambda params: Tuple(*map(Variable.deduced, params)))
+
+    @classmethod
+    def _construct_body(cls, itr):
+        if isinstance(itr, CodeBlock):
+            return itr
+        else:
+            return CodeBlock(*itr)
+
+class SubroutineCall(Token):
+    """ Represents a call to a subroutine in Fortran.
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.fnodes import SubroutineCall
+    >>> from sympy import fcode
+    >>> fcode(SubroutineCall('mysub', 'x y'.split()))
+    '       call mysub(x, y)'
+
+    """
+    __slots__ = _fields = ('name', 'subroutine_args')
+    _construct_name = staticmethod(_name)
+    _construct_subroutine_args = staticmethod(_mk_Tuple)
+
+
+class Do(Token):
+    """ Represents a Do loop in in Fortran.
+
+    Examples
+    ========
+
+    >>> from sympy import fcode, symbols
+    >>> from sympy.codegen.ast import aug_assign, Print
+    >>> from sympy.codegen.fnodes import Do
+    >>> i, n = symbols('i n', integer=True)
+    >>> r = symbols('r', real=True)
+    >>> body = [aug_assign(r, '+', 1/i), Print([i, r])]
+    >>> do1 = Do(body, i, 1, n)
+    >>> print(fcode(do1, source_format='free'))
+    do i = 1, n
+        r = r + 1d0/i
+        print *, i, r
+    end do
+    >>> do2 = Do(body, i, 1, n, 2)
+    >>> print(fcode(do2, source_format='free'))
+    do i = 1, n, 2
+        r = r + 1d0/i
+        print *, i, r
+    end do
+
+    """
+
+    __slots__ = _fields = ('body', 'counter', 'first', 'last', 'step', 'concurrent')
+    defaults = {'step': Integer(1), 'concurrent': false}
+    _construct_body = staticmethod(lambda body: CodeBlock(*body))
+    _construct_counter = staticmethod(sympify)
+    _construct_first = staticmethod(sympify)
+    _construct_last = staticmethod(sympify)
+    _construct_step = staticmethod(sympify)
+    _construct_concurrent = staticmethod(lambda arg: true if arg else false)
+
+
+class ArrayConstructor(Token):
+    """ Represents an array constructor.
+
+    Examples
+    ========
+
+    >>> from sympy import fcode
+    >>> from sympy.codegen.fnodes import ArrayConstructor
+    >>> ac = ArrayConstructor([1, 2, 3])
+    >>> fcode(ac, standard=95, source_format='free')
+    '(/1, 2, 3/)'
+    >>> fcode(ac, standard=2003, source_format='free')
+    '[1, 2, 3]'
+
+    """
+    __slots__ = _fields = ('elements',)
+    _construct_elements = staticmethod(_mk_Tuple)
+
+
+class ImpliedDoLoop(Token):
+    """ Represents an implied do loop in Fortran.
+
+    Examples
+    ========
+
+    >>> from sympy import Symbol, fcode
+    >>> from sympy.codegen.fnodes import ImpliedDoLoop, ArrayConstructor
+    >>> i = Symbol('i', integer=True)
+    >>> idl = ImpliedDoLoop(i**3, i, -3, 3, 2)  # -27, -1, 1, 27
+    >>> ac = ArrayConstructor([-28, idl, 28]) # -28, -27, -1, 1, 27, 28
+    >>> fcode(ac, standard=2003, source_format='free')
+    '[-28, (i**3, i = -3, 3, 2), 28]'
+
+    """
+    __slots__ = _fields = ('expr', 'counter', 'first', 'last', 'step')
+    defaults = {'step': Integer(1)}
+    _construct_expr = staticmethod(sympify)
+    _construct_counter = staticmethod(sympify)
+    _construct_first = staticmethod(sympify)
+    _construct_last = staticmethod(sympify)
+    _construct_step = staticmethod(sympify)
+
+
+class Extent(Basic):
+    """ Represents a dimension extent.
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.fnodes import Extent
+    >>> e = Extent(-3, 3)  # -3, -2, -1, 0, 1, 2, 3
+    >>> from sympy import fcode
+    >>> fcode(e, source_format='free')
+    '-3:3'
+    >>> from sympy.codegen.ast import Variable, real
+    >>> from sympy.codegen.fnodes import dimension, intent_out
+    >>> dim = dimension(e, e)
+    >>> arr = Variable('x', real, attrs=[dim, intent_out])
+    >>> fcode(arr.as_Declaration(), source_format='free', standard=2003)
+    'real*8, dimension(-3:3, -3:3), intent(out) :: x'
+
+    """
+    def __new__(cls, *args):
+        if len(args) == 2:
+            low, high = args
+            return Basic.__new__(cls, sympify(low), sympify(high))
+        elif len(args) == 0 or (len(args) == 1 and args[0] in (':', None)):
+            return Basic.__new__(cls)  # assumed shape
+        else:
+            raise ValueError("Expected 0 or 2 args (or one argument == None or ':')")
+
+    def _sympystr(self, printer):
+        if len(self.args) == 0:
+            return ':'
+        return ":".join(str(arg) for arg in self.args)
+
+assumed_extent = Extent() # or Extent(':'), Extent(None)
+
+
+def dimension(*args):
+    """ Creates a 'dimension' Attribute with (up to 7) extents.
+
+    Examples
+    ========
+
+    >>> from sympy import fcode
+    >>> from sympy.codegen.fnodes import dimension, intent_in
+    >>> dim = dimension('2', ':')  # 2 rows, runtime determined number of columns
+    >>> from sympy.codegen.ast import Variable, integer
+    >>> arr = Variable('a', integer, attrs=[dim, intent_in])
+    >>> fcode(arr.as_Declaration(), source_format='free', standard=2003)
+    'integer*4, dimension(2, :), intent(in) :: a'
+
+    """
+    if len(args) > 7:
+        raise ValueError("Fortran only supports up to 7 dimensional arrays")
+    parameters = []
+    for arg in args:
+        if isinstance(arg, Extent):
+            parameters.append(arg)
+        elif isinstance(arg, str):
+            if arg == ':':
+                parameters.append(Extent())
+            else:
+                parameters.append(String(arg))
+        elif iterable(arg):
+            parameters.append(Extent(*arg))
+        else:
+            parameters.append(sympify(arg))
+    if len(args) == 0:
+        raise ValueError("Need at least one dimension")
+    return Attribute('dimension', parameters)
+
+
+assumed_size = dimension('*')
+
+def array(symbol, dim, intent=None, *, attrs=(), value=None, type=None):
+    """ Convenience function for creating a Variable instance for a Fortran array.
+
+    Parameters
+    ==========
+
+    symbol : symbol
+    dim : Attribute or iterable
+        If dim is an ``Attribute`` it need to have the name 'dimension'. If it is
+        not an ``Attribute``, then it is passed to :func:`dimension` as ``*dim``
+    intent : str
+        One of: 'in', 'out', 'inout' or None
+    \\*\\*kwargs:
+        Keyword arguments for ``Variable`` ('type' & 'value')
+
+    Examples
+    ========
+
+    >>> from sympy import fcode
+    >>> from sympy.codegen.ast import integer, real
+    >>> from sympy.codegen.fnodes import array
+    >>> arr = array('a', '*', 'in', type=integer)
+    >>> print(fcode(arr.as_Declaration(), source_format='free', standard=2003))
+    integer*4, dimension(*), intent(in) :: a
+    >>> x = array('x', [3, ':', ':'], intent='out', type=real)
+    >>> print(fcode(x.as_Declaration(value=1), source_format='free', standard=2003))
+    real*8, dimension(3, :, :), intent(out) :: x = 1
+
+    """
+    if isinstance(dim, Attribute):
+        if str(dim.name) != 'dimension':
+            raise ValueError("Got an unexpected Attribute argument as dim: %s" % str(dim))
+    else:
+        dim = dimension(*dim)
+
+    attrs = list(attrs) + [dim]
+    if intent is not None:
+        if intent not in (intent_in, intent_out, intent_inout):
+            intent = {'in': intent_in, 'out': intent_out, 'inout': intent_inout}[intent]
+        attrs.append(intent)
+    if type is None:
+        return Variable.deduced(symbol, value=value, attrs=attrs)
+    else:
+        return Variable(symbol, type, value=value, attrs=attrs)
+
+def _printable(arg):
+    return String(arg) if isinstance(arg, str) else sympify(arg)
+
+
+def allocated(array):
+    """ Creates an AST node for a function call to Fortran's "allocated(...)"
+
+    Examples
+    ========
+
+    >>> from sympy import fcode
+    >>> from sympy.codegen.fnodes import allocated
+    >>> alloc = allocated('x')
+    >>> fcode(alloc, source_format='free')
+    'allocated(x)'
+
+    """
+    return FunctionCall('allocated', [_printable(array)])
+
+
+def lbound(array, dim=None, kind=None):
+    """ Creates an AST node for a function call to Fortran's "lbound(...)"
+
+    Parameters
+    ==========
+
+    array : Symbol or String
+    dim : expr
+    kind : expr
+
+    Examples
+    ========
+
+    >>> from sympy import fcode
+    >>> from sympy.codegen.fnodes import lbound
+    >>> lb = lbound('arr', dim=2)
+    >>> fcode(lb, source_format='free')
+    'lbound(arr, 2)'
+
+    """
+    return FunctionCall(
+        'lbound',
+        [_printable(array)] +
+        ([_printable(dim)] if dim else []) +
+        ([_printable(kind)] if kind else [])
+    )
+
+
+def ubound(array, dim=None, kind=None):
+    return FunctionCall(
+        'ubound',
+        [_printable(array)] +
+        ([_printable(dim)] if dim else []) +
+        ([_printable(kind)] if kind else [])
+    )
+
+
+def shape(source, kind=None):
+    """ Creates an AST node for a function call to Fortran's "shape(...)"
+
+    Parameters
+    ==========
+
+    source : Symbol or String
+    kind : expr
+
+    Examples
+    ========
+
+    >>> from sympy import fcode
+    >>> from sympy.codegen.fnodes import shape
+    >>> shp = shape('x')
+    >>> fcode(shp, source_format='free')
+    'shape(x)'
+
+    """
+    return FunctionCall(
+        'shape',
+        [_printable(source)] +
+        ([_printable(kind)] if kind else [])
+    )
+
+
+def size(array, dim=None, kind=None):
+    """ Creates an AST node for a function call to Fortran's "size(...)"
+
+    Examples
+    ========
+
+    >>> from sympy import fcode, Symbol
+    >>> from sympy.codegen.ast import FunctionDefinition, real, Return
+    >>> from sympy.codegen.fnodes import array, sum_, size
+    >>> a = Symbol('a', real=True)
+    >>> body = [Return((sum_(a**2)/size(a))**.5)]
+    >>> arr = array(a, dim=[':'], intent='in')
+    >>> fd = FunctionDefinition(real, 'rms', [arr], body)
+    >>> print(fcode(fd, source_format='free', standard=2003))
+    real*8 function rms(a)
+    real*8, dimension(:), intent(in) :: a
+    rms = sqrt(sum(a**2)*1d0/size(a))
+    end function
+
+    """
+    return FunctionCall(
+        'size',
+        [_printable(array)] +
+        ([_printable(dim)] if dim else []) +
+        ([_printable(kind)] if kind else [])
+    )
+
+
+def reshape(source, shape, pad=None, order=None):
+    """ Creates an AST node for a function call to Fortran's "reshape(...)"
+
+    Parameters
+    ==========
+
+    source : Symbol or String
+    shape : ArrayExpr
+
+    """
+    return FunctionCall(
+        'reshape',
+        [_printable(source), _printable(shape)] +
+        ([_printable(pad)] if pad else []) +
+        ([_printable(order)] if pad else [])
+    )
+
+
+def bind_C(name=None):
+    """ Creates an Attribute ``bind_C`` with a name.
+
+    Parameters
+    ==========
+
+    name : str
+
+    Examples
+    ========
+
+    >>> from sympy import fcode, Symbol
+    >>> from sympy.codegen.ast import FunctionDefinition, real, Return
+    >>> from sympy.codegen.fnodes import array, sum_, bind_C
+    >>> a = Symbol('a', real=True)
+    >>> s = Symbol('s', integer=True)
+    >>> arr = array(a, dim=[s], intent='in')
+    >>> body = [Return((sum_(a**2)/s)**.5)]
+    >>> fd = FunctionDefinition(real, 'rms', [arr, s], body, attrs=[bind_C('rms')])
+    >>> print(fcode(fd, source_format='free', standard=2003))
+    real*8 function rms(a, s) bind(C, name="rms")
+    real*8, dimension(s), intent(in) :: a
+    integer*4 :: s
+    rms = sqrt(sum(a**2)/s)
+    end function
+
+    """
+    return Attribute('bind_C', [String(name)] if name else [])
+
+class GoTo(Token):
+    """ Represents a goto statement in Fortran
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.fnodes import GoTo
+    >>> go = GoTo([10, 20, 30], 'i')
+    >>> from sympy import fcode
+    >>> fcode(go, source_format='free')
+    'go to (10, 20, 30), i'
+
+    """
+    __slots__ = _fields = ('labels', 'expr')
+    defaults = {'expr': none}
+    _construct_labels = staticmethod(_mk_Tuple)
+    _construct_expr = staticmethod(sympify)
+
+
+class FortranReturn(Token):
+    """ AST node explicitly mapped to a fortran "return".
+
+    Explanation
+    ===========
+
+    Because a return statement in fortran is different from C, and
+    in order to aid reuse of our codegen ASTs the ordinary
+    ``.codegen.ast.Return`` is interpreted as assignment to
+    the result variable of the function. If one for some reason needs
+    to generate a fortran RETURN statement, this node should be used.
+
+    Examples
+    ========
+
+    >>> from sympy.codegen.fnodes import FortranReturn
+    >>> from sympy import fcode
+    >>> fcode(FortranReturn('x'))
+    '       return x'
+
+    """
+    __slots__ = _fields = ('return_value',)
+    defaults = {'return_value': none}
+    _construct_return_value = staticmethod(sympify)
+
+
+class FFunction(Function):
+    _required_standard = 77
+
+    def _fcode(self, printer):
+        name = self.__class__.__name__
+        if printer._settings['standard'] < self._required_standard:
+            raise NotImplementedError("%s requires Fortran %d or newer" %
+                                      (name, self._required_standard))
+        return '{}({})'.format(name, ', '.join(map(printer._print, self.args)))
+
+
+class F95Function(FFunction):
+    _required_standard = 95
+
+
+class isign(FFunction):
+    """ Fortran sign intrinsic for integer arguments. """
+    nargs = 2
+
+
+class dsign(FFunction):
+    """ Fortran sign intrinsic for double precision arguments. """
+    nargs = 2
+
+
+class cmplx(FFunction):
+    """ Fortran complex conversion function. """
+    nargs = 2  # may be extended to (2, 3) at a later point
+
+
+class kind(FFunction):
+    """ Fortran kind function. """
+    nargs = 1
+
+
+class merge(F95Function):
+    """ Fortran merge function """
+    nargs = 3
+
+
+class _literal(Float):
+    _token: str
+    _decimals: int
+
+    def _fcode(self, printer, *args, **kwargs):
+        mantissa, sgnd_ex = ('%.{}e'.format(self._decimals) % self).split('e')
+        mantissa = mantissa.strip('0').rstrip('.')
+        ex_sgn, ex_num = sgnd_ex[0], sgnd_ex[1:].lstrip('0')
+        ex_sgn = '' if ex_sgn == '+' else ex_sgn
+        return (mantissa or '0') + self._token + ex_sgn + (ex_num or '0')
+
+
+class literal_sp(_literal):
+    """ Fortran single precision real literal """
+    _token = 'e'
+    _decimals = 9
+
+
+class literal_dp(_literal):
+    """ Fortran double precision real literal """
+    _token = 'd'
+    _decimals = 17
+
+
+class sum_(Token, Expr):
+    __slots__ = _fields = ('array', 'dim', 'mask')
+    defaults = {'dim': none, 'mask': none}
+    _construct_array = staticmethod(sympify)
+    _construct_dim = staticmethod(sympify)
+
+
+class product_(Token, Expr):
+    __slots__ = _fields = ('array', 'dim', 'mask')
+    defaults = {'dim': none, 'mask': none}
+    _construct_array = staticmethod(sympify)
+    _construct_dim = staticmethod(sympify)

.venv/lib/python3.12/site-packages/sympy/codegen/futils.py

@@ -0,0 +1,40 @@
+from itertools import chain
+from sympy.codegen.fnodes import Module
+from sympy.core.symbol import Dummy
+from sympy.printing.fortran import FCodePrinter
+
+""" This module collects utilities for rendering Fortran code. """
+
+
+def render_as_module(definitions, name, declarations=(), printer_settings=None):
+    """ Creates a ``Module`` instance and renders it as a string.
+
+    This generates Fortran source code for a module with the correct ``use`` statements.
+
+    Parameters
+    ==========
+
+    definitions : iterable
+        Passed to :class:`sympy.codegen.fnodes.Module`.
+    name : str
+        Passed to :class:`sympy.codegen.fnodes.Module`.
+    declarations : iterable
+        Passed to :class:`sympy.codegen.fnodes.Module`. It will be extended with
+        use statements, 'implicit none' and public list generated from ``definitions``.
+    printer_settings : dict
+        Passed to ``FCodePrinter`` (default: ``{'standard': 2003, 'source_format': 'free'}``).
+
+    """
+    printer_settings = printer_settings or {'standard': 2003, 'source_format': 'free'}
+    printer = FCodePrinter(printer_settings)
+    dummy = Dummy()
+    if isinstance(definitions, Module):
+        raise ValueError("This function expects to construct a module on its own.")
+    mod = Module(name, chain(declarations, [dummy]), definitions)
+    fstr = printer.doprint(mod)
+    module_use_str = '   %s\n' % '   \n'.join(['use %s, only: %s' % (k, ', '.join(v)) for
+                                                k, v in printer.module_uses.items()])
+    module_use_str += '   implicit none\n'
+    module_use_str += '   private\n'
+    module_use_str += '   public %s\n' % ', '.join([str(node.name) for node in definitions if getattr(node, 'name', None)])
+    return fstr.replace(printer.doprint(dummy), module_use_str)

.venv/lib/python3.12/site-packages/sympy/codegen/matrix_nodes.py

@@ -0,0 +1,71 @@
+"""
+Additional AST nodes for operations on matrices. The nodes in this module
+are meant to represent optimization of matrix expressions within codegen's
+target languages that cannot be represented by SymPy expressions.
+
+As an example, we can use :meth:`sympy.codegen.rewriting.optimize` and the
+``matin_opt`` optimization provided in :mod:`sympy.codegen.rewriting` to
+transform matrix multiplication under certain assumptions:
+
+    >>> from sympy import symbols, MatrixSymbol
+    >>> n = symbols('n', integer=True)
+    >>> A = MatrixSymbol('A', n, n)
+    >>> x = MatrixSymbol('x', n, 1)
+    >>> expr = A**(-1) * x
+    >>> from sympy import assuming, Q
+    >>> from sympy.codegen.rewriting import matinv_opt, optimize
+    >>> with assuming(Q.fullrank(A)):
+    ...     optimize(expr, [matinv_opt])
+    MatrixSolve(A, vector=x)
+"""
+
+from .ast import Token
+from sympy.matrices import MatrixExpr
+from sympy.core.sympify import sympify
+
+
+class MatrixSolve(Token, MatrixExpr):
+    """Represents an operation to solve a linear matrix equation.
+
+    Parameters
+    ==========
+
+    matrix : MatrixSymbol
+
+      Matrix representing the coefficients of variables in the linear
+      equation. This matrix must be square and full-rank (i.e. all columns must
+      be linearly independent) for the solving operation to be valid.
+
+    vector : MatrixSymbol
+
+      One-column matrix representing the solutions to the equations
+      represented in ``matrix``.
+
+    Examples
+    ========
+
+    >>> from sympy import symbols, MatrixSymbol
+    >>> from sympy.codegen.matrix_nodes import MatrixSolve
+    >>> n = symbols('n', integer=True)
+    >>> A = MatrixSymbol('A', n, n)
+    >>> x = MatrixSymbol('x', n, 1)
+    >>> from sympy.printing.numpy import NumPyPrinter
+    >>> NumPyPrinter().doprint(MatrixSolve(A, x))
+    'numpy.linalg.solve(A, x)'
+    >>> from sympy import octave_code
+    >>> octave_code(MatrixSolve(A, x))
+    'A \\\\ x'
+
+    """
+    __slots__ = _fields = ('matrix', 'vector')
+
+    _construct_matrix = staticmethod(sympify)
+    _construct_vector = staticmethod(sympify)
+
+    @property
+    def shape(self):
+        return self.vector.shape
+
+    def _eval_derivative(self, x):
+        A, b = self.matrix, self.vector
+        return MatrixSolve(A, b.diff(x) - A.diff(x) * MatrixSolve(A, b))

.venv/lib/python3.12/site-packages/sympy/codegen/numpy_nodes.py

@@ -0,0 +1,177 @@
+from sympy.core.function import Add, ArgumentIndexError, Function
+from sympy.core.power import Pow
+from sympy.core.singleton import S
+from sympy.core.sorting import default_sort_key
+from sympy.core.sympify import sympify
+from sympy.functions.elementary.exponential import exp, log
+from sympy.functions.elementary.miscellaneous import Max, Min
+from .ast import Token, none
+
+
+def _logaddexp(x1, x2, *, evaluate=True):
+    return log(Add(exp(x1, evaluate=evaluate), exp(x2, evaluate=evaluate), evaluate=evaluate))
+
+
+_two = S.One*2
+_ln2 = log(_two)
+
+
+def _lb(x, *, evaluate=True):
+    return log(x, evaluate=evaluate)/_ln2
+
+
+def _exp2(x, *, evaluate=True):
+    return Pow(_two, x, evaluate=evaluate)
+
+
+def _logaddexp2(x1, x2, *, evaluate=True):
+    return _lb(Add(_exp2(x1, evaluate=evaluate),
+                   _exp2(x2, evaluate=evaluate), evaluate=evaluate))
+
+
+class logaddexp(Function):
+    """ Logarithm of the sum of exponentiations of the inputs.
+
+    Helper class for use with e.g. numpy.logaddexp
+
+    See Also
+    ========
+
+    https://numpy.org/doc/stable/reference/generated/numpy.logaddexp.html
+    """
+    nargs = 2
+
+    def __new__(cls, *args):
+        return Function.__new__(cls, *sorted(args, key=default_sort_key))
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            wrt, other = self.args
+        elif argindex == 2:
+            other, wrt = self.args
+        else:
+            raise ArgumentIndexError(self, argindex)
+        return S.One/(S.One + exp(other-wrt))
+
+    def _eval_rewrite_as_log(self, x1, x2, **kwargs):
+        return _logaddexp(x1, x2)
+
+    def _eval_evalf(self, *args, **kwargs):
+        return self.rewrite(log).evalf(*args, **kwargs)
+
+    def _eval_simplify(self, *args, **kwargs):
+        a, b = (x.simplify(**kwargs) for x in self.args)
+        candidate = _logaddexp(a, b)
+        if candidate != _logaddexp(a, b, evaluate=False):
+            return candidate
+        else:
+            return logaddexp(a, b)
+
+
+class logaddexp2(Function):
+    """ Logarithm of the sum of exponentiations of the inputs in base-2.
+
+    Helper class for use with e.g. numpy.logaddexp2
+
+    See Also
+    ========
+
+    https://numpy.org/doc/stable/reference/generated/numpy.logaddexp2.html
+    """
+    nargs = 2
+
+    def __new__(cls, *args):
+        return Function.__new__(cls, *sorted(args, key=default_sort_key))
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            wrt, other = self.args
+        elif argindex == 2:
+            other, wrt = self.args
+        else:
+            raise ArgumentIndexError(self, argindex)
+        return S.One/(S.One + _exp2(other-wrt))
+
+    def _eval_rewrite_as_log(self, x1, x2, **kwargs):
+        return _logaddexp2(x1, x2)
+
+    def _eval_evalf(self, *args, **kwargs):
+        return self.rewrite(log).evalf(*args, **kwargs)
+
+    def _eval_simplify(self, *args, **kwargs):
+        a, b = (x.simplify(**kwargs).factor() for x in self.args)
+        candidate = _logaddexp2(a, b)
+        if candidate != _logaddexp2(a, b, evaluate=False):
+            return candidate
+        else:
+            return logaddexp2(a, b)
+
+
+class amin(Token):
+    """ Minimum value along an axis.
+
+    Helper class for use with e.g. numpy.amin
+
+
+    See Also
+    ========
+
+    https://numpy.org/doc/stable/reference/generated/numpy.amin.html
+    """
+    __slots__ = _fields = ('array', 'axis')
+    defaults = {'axis': none}
+    _construct_axis = staticmethod(sympify)
+
+
+class amax(Token):
+    """ Maximum value along an axis.
+
+    Helper class for use with e.g. numpy.amax
+
+
+    See Also
+    ========
+
+    https://numpy.org/doc/stable/reference/generated/numpy.amax.html
+    """
+    __slots__ = _fields = ('array', 'axis')
+    defaults = {'axis': none}
+    _construct_axis = staticmethod(sympify)
+
+
+class maximum(Function):
+    """ Element-wise maximum of array elements.
+
+    Helper class for use with e.g. numpy.maximum
+
+
+    See Also
+    ========
+
+    https://numpy.org/doc/stable/reference/generated/numpy.maximum.html
+    """
+
+    def _eval_rewrite_as_Max(self, *args):
+        return Max(*self.args)
+
+
+class minimum(Function):
+    """ Element-wise minimum of array elements.
+
+    Helper class for use with e.g. numpy.minimum
+
+
+    See Also
+    ========
+
+    https://numpy.org/doc/stable/reference/generated/numpy.minimum.html
+    """
+
+    def _eval_rewrite_as_Min(self, *args):
+        return Min(*self.args)

.venv/lib/python3.12/site-packages/sympy/codegen/pynodes.py

@@ -0,0 +1,11 @@
+from .abstract_nodes import List as AbstractList
+from .ast import Token
+
+
+class List(AbstractList):
+    pass
+
+
+class NumExprEvaluate(Token):
+    """represents a call to :class:`numexpr`s :func:`evaluate`"""
+    __slots__ = _fields = ('expr',)

.venv/lib/python3.12/site-packages/sympy/codegen/pyutils.py

@@ -0,0 +1,24 @@
+from sympy.printing.pycode import PythonCodePrinter
+
+""" This module collects utilities for rendering Python code. """
+
+
+def render_as_module(content, standard='python3'):
+    """Renders Python code as a module (with the required imports).
+
+    Parameters
+    ==========
+
+    standard :
+        See the parameter ``standard`` in
+        :meth:`sympy.printing.pycode.pycode`
+    """
+
+    printer = PythonCodePrinter({'standard':standard})
+    pystr = printer.doprint(content)
+    if printer._settings['fully_qualified_modules']:
+        module_imports_str = '\n'.join('import %s' % k for k in printer.module_imports)
+    else:
+        module_imports_str = '\n'.join(['from %s import %s' % (k, ', '.join(v)) for
+                                        k, v in printer.module_imports.items()])
+    return module_imports_str + '\n\n' + pystr

.venv/lib/python3.12/site-packages/sympy/codegen/rewriting.py

@@ -0,0 +1,357 @@
+"""
+Classes and functions useful for rewriting expressions for optimized code
+generation. Some languages (or standards thereof), e.g. C99, offer specialized
+math functions for better performance and/or precision.
+
+Using the ``optimize`` function in this module, together with a collection of
+rules (represented as instances of ``Optimization``), one can rewrite the
+expressions for this purpose::
+
+    >>> from sympy import Symbol, exp, log
+    >>> from sympy.codegen.rewriting import optimize, optims_c99
+    >>> x = Symbol('x')
+    >>> optimize(3*exp(2*x) - 3, optims_c99)
+    3*expm1(2*x)
+    >>> optimize(exp(2*x) - 1 - exp(-33), optims_c99)
+    expm1(2*x) - exp(-33)
+    >>> optimize(log(3*x + 3), optims_c99)
+    log1p(x) + log(3)
+    >>> optimize(log(2*x + 3), optims_c99)
+    log(2*x + 3)
+
+The ``optims_c99`` imported above is tuple containing the following instances
+(which may be imported from ``sympy.codegen.rewriting``):
+
+- ``expm1_opt``
+- ``log1p_opt``
+- ``exp2_opt``
+- ``log2_opt``
+- ``log2const_opt``
+
+
+"""
+from sympy.core.function import expand_log
+from sympy.core.singleton import S
+from sympy.core.symbol import Wild
+from sympy.functions.elementary.complexes import sign
+from sympy.functions.elementary.exponential import (exp, log)
+from sympy.functions.elementary.miscellaneous import (Max, Min)
+from sympy.functions.elementary.trigonometric import (cos, sin, sinc)
+from sympy.assumptions import Q, ask
+from sympy.codegen.cfunctions import log1p, log2, exp2, expm1
+from sympy.codegen.matrix_nodes import MatrixSolve
+from sympy.core.expr import UnevaluatedExpr
+from sympy.core.power import Pow
+from sympy.codegen.numpy_nodes import logaddexp, logaddexp2
+from sympy.codegen.scipy_nodes import cosm1, powm1
+from sympy.core.mul import Mul
+from sympy.matrices.expressions.matexpr import MatrixSymbol
+from sympy.utilities.iterables import sift
+
+
+class Optimization:
+    """ Abstract base class for rewriting optimization.
+
+    Subclasses should implement ``__call__`` taking an expression
+    as argument.
+
+    Parameters
+    ==========
+    cost_function : callable returning number
+    priority : number
+
+    """
+    def __init__(self, cost_function=None, priority=1):
+        self.cost_function = cost_function
+        self.priority=priority
+
+    def cheapest(self, *args):
+        return min(args, key=self.cost_function)
+
+
+class ReplaceOptim(Optimization):
+    """ Rewriting optimization calling replace on expressions.
+
+    Explanation
+    ===========
+
+    The instance can be used as a function on expressions for which
+    it will apply the ``replace`` method (see
+    :meth:`sympy.core.basic.Basic.replace`).
+
+    Parameters
+    ==========
+
+    query :
+        First argument passed to replace.
+    value :
+        Second argument passed to replace.
+
+    Examples
+    ========
+
+    >>> from sympy import Symbol
+    >>> from sympy.codegen.rewriting import ReplaceOptim
+    >>> from sympy.codegen.cfunctions import exp2
+    >>> x = Symbol('x')
+    >>> exp2_opt = ReplaceOptim(lambda p: p.is_Pow and p.base == 2,
+    ...     lambda p: exp2(p.exp))
+    >>> exp2_opt(2**x)
+    exp2(x)
+
+    """
+
+    def __init__(self, query, value, **kwargs):
+        super().__init__(**kwargs)
+        self.query = query
+        self.value = value
+
+    def __call__(self, expr):
+        return expr.replace(self.query, self.value)
+
+
+def optimize(expr, optimizations):
+    """ Apply optimizations to an expression.
+
+    Parameters
+    ==========
+
+    expr : expression
+    optimizations : iterable of ``Optimization`` instances
+        The optimizations will be sorted with respect to ``priority`` (highest first).
+
+    Examples
+    ========
+
+    >>> from sympy import log, Symbol
+    >>> from sympy.codegen.rewriting import optims_c99, optimize
+    >>> x = Symbol('x')
+    >>> optimize(log(x+3)/log(2) + log(x**2 + 1), optims_c99)
+    log1p(x**2) + log2(x + 3)
+
+    """
+
+    for optim in sorted(optimizations, key=lambda opt: opt.priority, reverse=True):
+        new_expr = optim(expr)
+        if optim.cost_function is None:
+            expr = new_expr
+        else:
+            expr = optim.cheapest(expr, new_expr)
+    return expr
+
+
+exp2_opt = ReplaceOptim(
+    lambda p: p.is_Pow and p.base == 2,
+    lambda p: exp2(p.exp)
+)
+
+
+_d = Wild('d', properties=[lambda x: x.is_Dummy])
+_u = Wild('u', properties=[lambda x: not x.is_number and not x.is_Add])
+_v = Wild('v')
+_w = Wild('w')
+_n = Wild('n', properties=[lambda x: x.is_number])
+
+sinc_opt1 = ReplaceOptim(
+    sin(_w)/_w, sinc(_w)
+)
+sinc_opt2 = ReplaceOptim(
+    sin(_n*_w)/_w, _n*sinc(_n*_w)
+)
+sinc_opts = (sinc_opt1, sinc_opt2)
+
+log2_opt = ReplaceOptim(_v*log(_w)/log(2), _v*log2(_w), cost_function=lambda expr: expr.count(
+    lambda e: (  # division & eval of transcendentals are expensive floating point operations...
+        e.is_Pow and e.exp.is_negative  # division
+        or (isinstance(e, (log, log2)) and not e.args[0].is_number))  # transcendental
+    )
+)
+
+log2const_opt = ReplaceOptim(log(2)*log2(_w), log(_w))
+
+logsumexp_2terms_opt = ReplaceOptim(
+    lambda l: (isinstance(l, log)
+               and l.args[0].is_Add
+               and len(l.args[0].args) == 2
+               and all(isinstance(t, exp) for t in l.args[0].args)),
+    lambda l: (
+        Max(*[e.args[0] for e in l.args[0].args]) +
+        log1p(exp(Min(*[e.args[0] for e in l.args[0].args])))
+    )
+)
+
+
+class FuncMinusOneOptim(ReplaceOptim):
+    """Specialization of ReplaceOptim for functions evaluating "f(x) - 1".
+
+    Explanation
+    ===========
+
+    Numerical functions which go toward one as x go toward zero is often best
+    implemented by a dedicated function in order to avoid catastrophic
+    cancellation. One such example is ``expm1(x)`` in the C standard library
+    which evaluates ``exp(x) - 1``. Such functions preserves many more
+    significant digits when its argument is much smaller than one, compared
+    to subtracting one afterwards.
+
+    Parameters
+    ==========
+
+    func :
+        The function which is subtracted by one.
+    func_m_1 :
+        The specialized function evaluating ``func(x) - 1``.
+    opportunistic : bool
+        When ``True``, apply the transformation as long as the magnitude of the
+        remaining number terms decreases. When ``False``, only apply the
+        transformation if it completely eliminates the number term.
+
+    Examples
+    ========
+
+    >>> from sympy import symbols, exp
+    >>> from sympy.codegen.rewriting import FuncMinusOneOptim
+    >>> from sympy.codegen.cfunctions import expm1
+    >>> x, y = symbols('x y')
+    >>> expm1_opt = FuncMinusOneOptim(exp, expm1)
+    >>> expm1_opt(exp(x) + 2*exp(5*y) - 3)
+    expm1(x) + 2*expm1(5*y)
+
+
+    """
+
+    def __init__(self, func, func_m_1, opportunistic=True):
+        weight = 10  # <-- this is an arbitrary number (heuristic)
+        super().__init__(lambda e: e.is_Add, self.replace_in_Add,
+                         cost_function=lambda expr: expr.count_ops() - weight*expr.count(func_m_1))
+        self.func = func
+        self.func_m_1 = func_m_1
+        self.opportunistic = opportunistic
+
+    def _group_Add_terms(self, add):
+        numbers, non_num = sift(add.args, lambda arg: arg.is_number, binary=True)
+        numsum = sum(numbers)
+        terms_with_func, other = sift(non_num, lambda arg: arg.has(self.func), binary=True)
+        return numsum, terms_with_func, other
+
+    def replace_in_Add(self, e):
+        """ passed as second argument to Basic.replace(...) """
+        numsum, terms_with_func, other_non_num_terms = self._group_Add_terms(e)
+        if numsum == 0:
+            return e
+        substituted, untouched = [], []
+        for with_func in terms_with_func:
+            if with_func.is_Mul:
+                func, coeff = sift(with_func.args, lambda arg: arg.func == self.func, binary=True)
+                if len(func) == 1 and len(coeff) == 1:
+                    func, coeff = func[0], coeff[0]
+                else:
+                    coeff = None
+            elif with_func.func == self.func:
+                func, coeff = with_func, S.One
+            else:
+                coeff = None
+
+            if coeff is not None and coeff.is_number and sign(coeff) == -sign(numsum):
+                if self.opportunistic:
+                    do_substitute = abs(coeff+numsum) < abs(numsum)
+                else:
+                    do_substitute = coeff+numsum == 0
+
+                if do_substitute:  # advantageous substitution
+                    numsum += coeff
+                    substituted.append(coeff*self.func_m_1(*func.args))
+                    continue
+            untouched.append(with_func)
+
+        return e.func(numsum, *substituted, *untouched, *other_non_num_terms)
+
+    def __call__(self, expr):
+        alt1 = super().__call__(expr)
+        alt2 = super().__call__(expr.factor())
+        return self.cheapest(alt1, alt2)
+
+
+expm1_opt = FuncMinusOneOptim(exp, expm1)
+cosm1_opt = FuncMinusOneOptim(cos, cosm1)
+powm1_opt = FuncMinusOneOptim(Pow, powm1)
+
+log1p_opt = ReplaceOptim(
+    lambda e: isinstance(e, log),
+    lambda l: expand_log(l.replace(
+        log, lambda arg: log(arg.factor())
+    )).replace(log(_u+1), log1p(_u))
+)
+
+def create_expand_pow_optimization(limit, *, base_req=lambda b: b.is_symbol):
+    """ Creates an instance of :class:`ReplaceOptim` for expanding ``Pow``.
+
+    Explanation
+    ===========
+
+    The requirements for expansions are that the base needs to be a symbol
+    and the exponent needs to be an Integer (and be less than or equal to
+    ``limit``).
+
+    Parameters
+    ==========
+
+    limit : int
+         The highest power which is expanded into multiplication.
+    base_req : function returning bool
+         Requirement on base for expansion to happen, default is to return
+         the ``is_symbol`` attribute of the base.
+
+    Examples
+    ========
+
+    >>> from sympy import Symbol, sin
+    >>> from sympy.codegen.rewriting import create_expand_pow_optimization
+    >>> x = Symbol('x')
+    >>> expand_opt = create_expand_pow_optimization(3)
+    >>> expand_opt(x**5 + x**3)
+    x**5 + x*x*x
+    >>> expand_opt(x**5 + x**3 + sin(x)**3)
+    x**5 + sin(x)**3 + x*x*x
+    >>> opt2 = create_expand_pow_optimization(3, base_req=lambda b: not b.is_Function)
+    >>> opt2((x+1)**2 + sin(x)**2)
+    sin(x)**2 + (x + 1)*(x + 1)
+
+    """
+    return ReplaceOptim(
+        lambda e: e.is_Pow and base_req(e.base) and e.exp.is_Integer and abs(e.exp) <= limit,
+        lambda p: (
+            UnevaluatedExpr(Mul(*([p.base]*+p.exp), evaluate=False)) if p.exp > 0 else
+            1/UnevaluatedExpr(Mul(*([p.base]*-p.exp), evaluate=False))
+        ))
+
+# Optimization procedures for turning A**(-1) * x into MatrixSolve(A, x)
+def _matinv_predicate(expr):
+    # TODO: We should be able to support more than 2 elements
+    if expr.is_MatMul and len(expr.args) == 2:
+        left, right = expr.args
+        if left.is_Inverse and right.shape[1] == 1:
+            inv_arg = left.arg
+            if isinstance(inv_arg, MatrixSymbol):
+                return bool(ask(Q.fullrank(left.arg)))
+
+    return False
+
+def _matinv_transform(expr):
+    left, right = expr.args
+    inv_arg = left.arg
+    return MatrixSolve(inv_arg, right)
+
+
+matinv_opt = ReplaceOptim(_matinv_predicate, _matinv_transform)
+
+
+logaddexp_opt = ReplaceOptim(log(exp(_v)+exp(_w)), logaddexp(_v, _w))
+logaddexp2_opt = ReplaceOptim(log(Pow(2, _v)+Pow(2, _w)), logaddexp2(_v, _w)*log(2))
+
+# Collections of optimizations:
+optims_c99 = (expm1_opt, log1p_opt, exp2_opt, log2_opt, log2const_opt)
+
+optims_numpy = optims_c99 + (logaddexp_opt, logaddexp2_opt,) + sinc_opts
+
+optims_scipy = (cosm1_opt, powm1_opt)

.venv/lib/python3.12/site-packages/sympy/codegen/scipy_nodes.py

@@ -0,0 +1,79 @@
+from sympy.core.function import Add, ArgumentIndexError, Function
+from sympy.core.power import Pow
+from sympy.core.singleton import S
+from sympy.functions.elementary.exponential import log
+from sympy.functions.elementary.trigonometric import cos, sin
+
+
+def _cosm1(x, *, evaluate=True):
+    return Add(cos(x, evaluate=evaluate), -S.One, evaluate=evaluate)
+
+
+class cosm1(Function):
+    """ Minus one plus cosine of x, i.e. cos(x) - 1. For use when x is close to zero.
+
+    Helper class for use with e.g. scipy.special.cosm1
+    See: https://docs.scipy.org/doc/scipy/reference/generated/scipy.special.cosm1.html
+    """
+    nargs = 1
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            return -sin(*self.args)
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+    def _eval_rewrite_as_cos(self, x, **kwargs):
+        return _cosm1(x)
+
+    def _eval_evalf(self, *args, **kwargs):
+        return self.rewrite(cos).evalf(*args, **kwargs)
+
+    def _eval_simplify(self, **kwargs):
+        x, = self.args
+        candidate = _cosm1(x.simplify(**kwargs))
+        if candidate != _cosm1(x, evaluate=False):
+            return candidate
+        else:
+            return cosm1(x)
+
+
+def _powm1(x, y, *, evaluate=True):
+    return Add(Pow(x, y, evaluate=evaluate), -S.One, evaluate=evaluate)
+
+
+class powm1(Function):
+    """ Minus one plus x to the power of y, i.e. x**y - 1. For use when x is close to one or y is close to zero.
+
+    Helper class for use with e.g. scipy.special.powm1
+    See: https://docs.scipy.org/doc/scipy/reference/generated/scipy.special.powm1.html
+    """
+    nargs = 2
+
+    def fdiff(self, argindex=1):
+        """
+        Returns the first derivative of this function.
+        """
+        if argindex == 1:
+            return Pow(self.args[0], self.args[1])*self.args[1]/self.args[0]
+        elif argindex == 2:
+            return log(self.args[0])*Pow(*self.args)
+        else:
+            raise ArgumentIndexError(self, argindex)
+
+    def _eval_rewrite_as_Pow(self, x, y, **kwargs):
+        return _powm1(x, y)
+
+    def _eval_evalf(self, *args, **kwargs):
+        return self.rewrite(Pow).evalf(*args, **kwargs)
+
+    def _eval_simplify(self, **kwargs):
+        x, y = self.args
+        candidate = _powm1(x.simplify(**kwargs), y.simplify(**kwargs))
+        if candidate != _powm1(x, y, evaluate=False):
+            return candidate
+        else:
+            return powm1(x, y)