phanerozoic/Coq-Equations · Datasets at Hugging Face

fact stringlengths 3 2.59k	type stringclasses 20 values	library stringclasses 4 values	imports listlengths 0 18	filename stringclasses 207 values	symbolic_name stringlengths 1 36	docstring stringclasses 269 values
bool : Set := true : bool \| false : bool ]] We can define the boolean negation as follows: *) Equations neg (b : bool) : bool := neg true := false; neg false := true.	Inductive	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	bool	null
neg (b : bool) : bool := neg true := false; neg false := true.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	neg	* Inductive types In its simplest form, [Equations] allows to define functions on inductive datatypes. Take for example the booleans defined as an inductive type with two constructors [true] and [false]: [[ Inductive bool : Set := true : bool \| false : bool ]] We can define the boolean negation as follows:
neg_inv : forall b, neg (neg b) = b.	Lemma	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	neg_inv	null
neg_ind : bool -> bool -> Prop := \| neg_ind_equation_1 : neg_ind true false \| neg_ind_equation_2 : neg_ind false true ]] Along with a proof of [Π b, neg_ind b (neg b)], we can eliminate any call to [neg] specializing its argument and result in a single command.	Inductive	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	neg_ind	null
list {A} : Type := nil : list \| cons : A -> list -> list.	Inductive	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	list	* Reasoning principles In the setting of a proof assistant like Coq, we need not only the ability to define complex functions but also get good reasoning support for them. Practically, this translates to the ability to simplify applications of functions appearing in the goal and to give strong enough proof principles for (recursive) definitions. [Equations] provides this through an automatic generation of proofs related to the function. Namely, each defining equation gives rise to a lemma stating the equality between the left and right hand sides. These equations can be used as rewrite rules for simplification during proofs, without having to rely on the fragile simplifications implemented by raw reduction. We can also generate the inductive graph of any [Equations] definition, giving the strongest elimination principle on the function. I.e., for [neg] the inductive graph is defined as: [[ Inductive neg_ind : bool -> bool -> Prop := \| neg_ind_equation_1 : neg_ind true false \| neg_ind_equation_2 : neg_ind false true ]] Along with a proof of [Π b, neg_ind b (neg b)], we can eliminate any call to [neg] specializing its argument and result in a single command. Suppose we want to show that [neg] is involutive for example, our goal will look like: [[ b : bool ============================ neg (neg b) = b ]] An application of the tactic [funelim (neg b)] will produce two goals corresponding to the splitting done in [neg]: [neg false = true] and [neg true = false]. These correspond exactly to the rewriting lemmas generated for [neg]. In the following sections we will show how these ideas generalize to more complex types and definitions involving dependencies, overlapping clauses and recursion. * Building up ** Polymorphism Coq's inductive types can be parameterized by types, giving polymorphic datatypes. For example the list datatype is defined as:
tail {A} (l : list A) : list A := tail nil := nil ; tail (cons a v) := v.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	tail	No special support for polymorphism is needed, as type arguments are treated like regular arguments in dependent type theories. Note however that one cannot match on type arguments, there is no intensional type analysis. We can write the polymorphic [tail] function as follows:
app {A} (l l' : list A) : list A := app nil l' := l' ; app (cons a l) l' := cons a (app l l').	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	app	** Recursive inductive types Of course with inductive types comes recursion. Coq accepts a subset of the structurally recursive definitions by default (it is incomplete due to its syntactic nature). We will use this as a first step towards a more robust treatment of recursion via well-founded relations. A classical example is list concatenation:
filter {A} (l : list A) (p : A -> bool) : list A := filter nil p := nil ; filter (cons a l) p with p a => { filter (cons a l) p true := a :: filter l p ; filter (cons a l) p false := filter l p }.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	filter	** Moving to the left The structure of real programs is richer than a simple case tree on the original arguments in general. In the course of a computation, we might want to scrutinize intermediate results (e.g. coming from function calls) to produce an answer. This literally means adding a new pattern to the left of our equations made available for further refinement. This concept is know as with clauses in the Agda %\cite{norell:thesis}% community and was first presented and implemented in the Epigram language %\cite{DBLP:journals/jfp/McBrideM04}%. The compilation of with clauses and its treatment for generating equations and the induction principle are quite involved in the presence of dependencies, but the basic idea is to add a new case analysis to the program. To compute the type of the new subprogram, we actually abstract the discriminee term from the expected type of the clause, so that the type can get refined in the subprogram. In the non-dependent case this does not change anything though. Each [with] node generates an auxiliary definition from the clauses in the curly brackets, taking the additional object as argument. The equation for the with node will simply be an indirection to the auxiliary definition and simplification will continue as usual with the auxiliary definition's rewrite rules.
filter' {A} (l : list A) (p : A -> bool) : list A := \| [], p => [] \| a :: l, p with p a => { \| true => a :: filter' l p \| false => filter' l p }.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	filter	A more compact syntax can be used to avoid repeating the same patterns in multiple clauses and focus on the patterns that matter. When a clause starts with `\|`, a list of patterns separated by "," or "\|" can be provided in open syntax, without parentheses. They should match the explicit arguments of the current problem. Under a `with` node, they should match the variable(s) introduced by the `with` construct. When using "\|", the ";" at the end of a clause becomes optional.
unzip {A B} (l : list (A * B)) : list A * list B := unzip nil := (nil, nil) ; unzip (cons p l) with unzip l => { unzip (cons (pair a b) l) (pair la lb) := (a :: la, b :: lb) }.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	unzip	A common use of with clauses is to scrutinize recursive results like the following:
equal (n m : nat) : { n = m } + { n <> m } := equal O O := left eq_refl ; equal (S n) (S m) with equal n m := { equal (S n) (S ?(n)) (left eq_refl) := left eq_refl ; equal (S n) (S m) (right p) := right _ } ; equal x y := right _.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	equal	* Dependent types Coq supports writing dependent functions, in other words, it gives the ability to make the results _type_ depend on actual _values_, like the arguments of the function. A simple example is given below of a function which decides the equality of two natural numbers, returning a sum type carrying proofs of the equality or disequality of the arguments. The sum type [{ A } + { B }] is a constructive variant of disjunction that can be used in programs to give at the same time a boolean algorithmic information (are we in branch [A] or [B]) and a _logical_ information (a proof witness of [A] or [B]). Hence its constructors [left] and [right] take proofs as arguments. The [eq_refl] proof term is the single proof of [x = x] (the [x] is generaly infered automatically).
head {A} (l : list A) (pf : l <> nil) : A := head nil pf with pf eq_refl := { \| ! }; head (cons a v) _ := a.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	head	Of particular interest here is the inner program refining the recursive result. As [equal n m] is of type [{ n = m } + { n <> m }] we have two cases to consider: - Either we are in the [left p] case, and we know that [p] is a proof of [n = m], in which case we can do a nested match on [p]. The result of matching this equality proof is to unify [n] and [m], hence the left hand side patterns become [S n] and [S ?(n)] and the return type of this branch is refined to [{ n = n } + { n <> n }]. We can easily provide a proof for the left case. - In the right case, we mark the proof unfilled with an underscore. This will generate an obligation for the hole, that can be filled automatically by a predefined tactic or interactively by the user in proof mode (this uses the same obligation mechanism as the Program extension %\cite{sozeau.Coq/FingerTrees/article}%). In this case the automatic tactic is able to derive by itself that [n <> m -> S n <> S m]. Dependent types are also useful to turn partial functions into total functions by restricting their domain. Typically, we can force the list passed to [head] to be non-empty using the specification:
eq (A : Type) (x : A) : A -> Prop := eq_refl : eq A x x.	Inductive	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	eq	null
eqt {A} (x y z : A) (p : x = y) (q : y = z) : x = z := eqt x ?(x) ?(x) eq_refl eq_refl := eq_refl.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	eqt	Inductive families The next step is to make constraints such as non-emptiness part of the datatype itself. This capability is provided through inductive families in Coq %\cite{paulin93tlca}%, which are a similar concept to the generalization of algebraic datatypes to GADTs in functional languages like Haskell %\cite{GADTcomplete}%. Families provide a way to associate to each constructor a different type, making it possible to give specific information about a value in its type. * Equality The alma mater of inductive families is the propositional equality [eq] defined as: [[ Inductive eq (A : Type) (x : A) : A -> Prop := eq_refl : eq A x x. ]] Equality is a polymorphic relation on [A]. (The [Prop] sort (or kind) categorizes propositions, while the [Set] sort, equivalent to $\star$ in Haskell categorizes computational types.) Equality is _parameterized_ by a value [x] of type [A] and _indexed_ by another value of type [A]. Its single constructor states that equality is reflexive, so the only way to build an object of [eq x y] is if [x ~= y], that is if [x] is definitionaly equal to [y]. Now what is the elimination principle associated to this inductive family? It is the good old Leibniz substitution principle: [[ forall (A : Type) (x : A) (P : A -> Type), P x -> forall y : A, x = y -> P y ]] Provided a proof that [x = y], we can create on object of type [P y] from an existing object of type [P x]. This substitution principle is enough to show that equality is symmetric and transitive. For example we can use pattern-matching on equality proofs to show:
vmap {A B} (f : A -> B) {n} (v : vector A n) : vector B n := vmap f (n:=?(0)) Vnil := Vnil ; vmap f (Vcons a v) := Vcons (f a) (vmap f v).	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	vmap	null
vtail {A n} (v : vector A (S n)) : vector A n := vtail (Vcons a v') := v'.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	vtail	Here the value of the index representing the size of the vector is directly determined by the constructor, hence in the case tree we have no need to eliminate [n]. This means in particular that the function [vmap] does not do any computation with [n], and the argument could be eliminated in the extracted code. In other words, it provides only _logical_ information about the shape of [v] but no computational information. The [vmap] function works on every member of the [vector] family, but some functions may work only for some subfamilies, for example [vtail]:
NoConfusion for nat.	Derive	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	NoConfusion	** Derived notions, No-Confusion For this to work smoothlty, the package requires some derived definitions on each (indexed) family, which can be generated automatically using the generic [Derive] command. Here we ask to generate the signature, heterogeneous no-confusion and homogeneous no-confusion principles for vectors:
Signature NoConfusion NoConfusionHom for vector.	Derive	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	Signature	null
diag {A n} (v : vector (vector A n) n) : vector A n := diag (n:=O) Vnil := Vnil ; diag (n:=S _) (Vcons (Vcons a v) v') := Vcons a (diag (vmap vtail v')).	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	diag	The precise specification of these derived definitions can be found in the manual section %(\S \ref{manual})%. Signature is used to "pack" a value in an inductive family with its index, e.g. the "total space" of every index and value of the family. This can be used to derive the heterogeneous no-confusion principle for the family, which allows to discriminate between objects in potentially different instances/fibers of the family, or deduce injectivity of each constructor. The [NoConfusionHom] variant derives the homogeneous no-confusion principle between two objects in the _same_ instance of the family, e.g. to simplify equations of the form [Vnil = Vnil :> vector A 0]. This last principle can only be defined when pattern-matching on the inductive family does not require the [K] axiom and will otherwise fail. ** Unification and indexed datatypes Back to our example, of course the equations and the induction principle are simplified in a similar way. If we encounter a call to [vtail] in a proof, we can use the following elimination principle to simplify both the call and the argument which will be automatically substituted by an object of the form [Vcons _ _ _]:[[ forall P : forall (A : Type) (n : nat), vector A (S n) -> vector A n -> Prop, (forall (A : Type) (n : nat) (a : A) (v : vector A n), P A n (Vcons a v) v) -> forall (A : Type) (n : nat) (v : vector A (S n)), P A n v (vtail v) ]] As a witness of the power of the unification, consider the following function which computes the diagonal of a square matrix of size [n * n].
id (n : nat) : nat by wf n lt := id 0 := 0; id (S n') := S (id n').	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	id	Indeed, Coq cannot guess the decreasing argument of this fixpoint using its limited syntactic guard criterion: [vmap vtail v'] cannot be seen to be a (large) subterm of [v'] using this criterion, even if it is clearly "smaller". In general, it can also be the case that the compilation algorithm introduces decorations to the proof term that prevent the syntactic guard check from seeing that the definition is structurally recursive. To aleviate this problem, [Equations] provides support for _well-founded_ recursive definitions which do not rely on syntactic checks. The simplest example of this is using the [lt] order on natural numbers to define a recursive definition of identity:
Subterm for vector.	Derive	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	Subterm	Here [id] is defined by well-founded recursion on [lt] on the (only) argument [n] using the [by wf] annotation. At recursive calls of [id], obligations are generated to show that the arguments effectively decrease according to this relation. Here the proof that [n' < S n'] is discharged automatically. Wellfounded recursion on arbitrary dependent families is not as easy to use, as in general the relations on families are _heterogeneous_, as they must relate inhabitants of potentially different instances of the family. [Equations] provides a [Derive] command to generate the subterm relation on any such inductive family and derive the well-foundedness of its transitive closure. This provides course-of-values or so-called "mathematical" induction on these objects, reflecting the structural recursion criterion in the logic.
t_direct_subterm (A : Type) : forall n n0 : nat, vector A n -> vector A n0 -> Prop := t_direct_subterm_1_1 : forall (h : A) (n : nat) (H : vector A n), t_direct_subterm A n (S n) H (Vcons h H) ]] That is, there is only one recursive subterm, for the subvector in the [Vcons] constructor.	Inductive	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	t_direct_subterm	null
unzip {n} (v : vector (A * B) n) : vector A n * vector B n by wf (signature_pack v) (@t_subterm (A * B)) := unzip Vnil := (Vnil, Vnil) ; unzip (Vector.cons (pair x y) v) with unzip v := { \| pair xs ys := (Vector.cons x xs, Vector.cons y ys) }.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	unzip	We can use the packed relation to do well-founded recursion on the vector. Note that we do a recursive call on a substerm of type [vector A n] which must be shown smaller than a [vector A (S n)]. They are actually compared at the packed type [{ n : nat & vector A n}]. The default obligation tactic defined in [Equations.Init] includes a proof-search for [subterm] proofs which can resolve the recursive call obligation automatically in this case.
diag' {A n} (v : vector (vector A n) n) : vector A n by wf n := diag' Vnil := Vnil ; diag' (Vcons (Vcons a v) v') := Vcons a (diag' (vmap vtail v')).	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	diag	For the diagonal, it is easier to give [n] as the decreasing argument of the function, even if the pattern-matching itself is on vectors:
uipa : forall A, UIP A.	Axiom	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	uipa	The user must declare this axiom itself, as an instance of the [UIP] class.
Instance uipa.	Existing	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	Instance	null
K {A} (x : A) (P : x = x -> Type) (p : P eq_refl) (H : x = x) : P H := K x P p eq_refl := p.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	K	In this case the following definition uses the [UIP] axiom just declared.
allows however to use constructive proofs of UIP for types enjoying decidable equality.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	allows	null
K' (x : nat) (P : x = x -> Type) (p : P eq_refl) (H : x = x) : P H := K' x P p eq_refl := p.	Equations	doc	[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]	doc/equations_intro.v	K	Note that the definition loses its computational content: it will get stuck on an axiom. We hence do not recommend its use. Equations allows however to use constructive proofs of UIP for types enjoying decidable equality. The following example relies on an instance of the [EqDec] typeclass for natural numbers, from which we can automatically derive a [UIP nat] instance. Note that the computational behavior of this definition on open terms is not to reduce to [p] but pattern-matches on the decidable equality proof. However the defining equation still holds as a _propositional_ equality, and the definition of K' is axiom-free.
rev_acc {A} (l : list A) : list A := rev_acc l := go [] l where go : list A -> list A -> list A := go acc [] := acc; go acc (hd :: tl) := go (hd :: acc) tl.	Equations	examples	[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]	examples/accumulator.v	rev_acc	** Worker/wrapper The most standard example is an efficient implementation of list reversal. Instead of growing the stack by the size of the list, we accumulate a partially reverted list as a new argument of our function. We implement this using a [go] auxilliary function defined recursively and pattern matching on the list.
rev_acc_eq : forall {A} (l : list A), rev_acc l = rev l.	Lemma	examples	[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]	examples/accumulator.v	rev_acc_eq	A typical issue with such accumulating functions is that one has to write lemmas in two versions, once about the internal [go] function and then on its wrapper. Using the functional elimination principle associated to [rev_acc], we can show both properties simultaneously.
indexes : list nat -> list nat := indexes l := go [] (length l) where go : list nat -> nat -> list nat := go acc 0 := acc; go acc (S n) := go (n :: acc) n.	Equations	examples	[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]	examples/accumulator.v	indexes	** Programm equivalence with worker/wrappers Finally we show how the eliminator can be used to prove program equivalences involving a worker/wrapper definition. Here [indexes l] computes the list [0..\|l\|-1] of valid indexes in the list [l].
indexes_spec (l : list nat) : Forall (fun x => x < length l) (indexes l).	Lemma	examples	[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]	examples/accumulator.v	indexes_spec	Clearly, all indexes in the resulting list should be smaller than [length l]:
interval_large x y : ~ x < y -> interval x y = [].	Lemma	examples	[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]	examples/accumulator.v	interval_large	We prove a simple lemmas on [interval]:
indexes_interval l : indexes l = interval 0 (length l).	Lemma	examples	[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]	examples/accumulator.v	indexes_interval	One can show that [indexes l] produces the interval [0..\|l\|-1] using [indexes_elim]. The recursion invariant for [indexes_go] records that [acc] corresponds to a partial interval [n..\|l\|-1] during the computation, and is finally completed into [0..\|l\|-1] by the end of the computation. We use the previous lemmas as helpers.
Eq (A : Type) := { eqb : A -> A -> bool; eqb_spec : forall x y, reflect (x = y) (eqb x y) }.	Class	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	Eq	null
fin_eq {k} (f f' : fin k) : bool := fin_eq fz fz => true; fin_eq (fs f) (fs f') => fin_eq f f'; fin_eq _ _ => false.	Equations	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	fin_eq	null
fin_Eq k : Eq (fin k).	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	fin_Eq	null
bool_Eq : Eq bool.	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	bool_Eq	null
prod_eq A B : Eq A -> Eq B -> Eq (A * B).	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	prod_eq	null
option_eq {A : Type} {E:Eq A} (o o' : option A) : bool := option_eq None None := true; option_eq (Some o) (Some o') := eqb o o'; option_eq _ _ := false.	Equations	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	option_eq	null
option_Eq A : Eq A -> Eq (option A).	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	option_Eq	null
eq_fin_fn {k} (f g : fin k -> A) : bool := eq_fin_fn (k:=0) f g := true; eq_fin_fn (k:=S k) f g := eqb (f fz) (g fz) && eq_fin_fn (fun n => f (fs n)) (fun n => g (fs n)).	Equations	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	eq_fin_fn	null
Eq_graph k : Eq (fin k -> A).	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	Eq_graph	null
dec_rel {X:Type} (R : X → X → Prop) := ∀ x y, {R x y} + {not (R x y)}.	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	dec_rel	null
WFT : Type := \| ZT : WFT \| SUP : (X -> WFT) -> WFT.	Inductive	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	WFT	null
NoConfusion Subterm for WFT.	Derive	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	NoConfusion	null
sec_disj (R : X -> X -> Prop) x y z := R y z \/ R x y.	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	sec_disj	null
SecureBy (R : X -> X -> Prop) (p : WFT) : Prop := match p with \| ZT => forall x y, R x y \| SUP f => forall x, SecureBy (fun y z => R y z \/ R x y) (f x) end.	Fixpoint	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	SecureBy	null
SecureBy_mon p (R' S : X -> X -> Prop) (H : forall x y, R' x y -> S x y) : SecureBy R' p -> SecureBy S p.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	SecureBy_mon	null
almost_full (R : X -> X -> Prop) := exists p, SecureBy R p.	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	almost_full	null
af_tree_iter {x : X} (accX : Acc R x) := match accX with \| Acc_intro f => SUP (fun y => match decR y x with \| left Ry => af_tree_iter (f y Ry) \| right _ => ZT end) end.	Fixpoint	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	af_tree_iter	null
af_tree : X → WFT := fun x => af_tree_iter (wfR x).	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	af_tree	null
secure_from_wf : SecureBy (fun x y => not (R y x)) (SUP af_tree).	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	secure_from_wf	null
af_from_wf : almost_full (fun x y => not (R y x)).	Corollary	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	af_from_wf	null
AlmostFull {X} (R : X -> X -> Prop) := is_almost_full : almost_full R.	Class	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	AlmostFull	null
#[export] Instance proper_af X : Proper (relation_equivalence ==> iff) (@AlmostFull X).	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	proper_af	null
#[export] Instance almost_full_le : AlmostFull Peano.le.	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	almost_full_le	null
clos_trans_n1_left {R : X -> X -> Prop} x y z : R x y -> clos_trans_n1 _ R y z -> clos_trans_n1 _ R x z.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	clos_trans_n1_left	null
clos_trans_1n_n1 {R : X -> X -> Prop} x y : clos_trans_1n _ R x y -> clos_trans_n1 _ R x y.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	clos_trans_1n_n1	null
clos_refl_trans_right {R : X -> X -> Prop} x y z : R y z -> clos_refl_trans _ R x y -> clos_trans_n1 _ R x z.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	clos_refl_trans_right	null
clos_trans_1n_right {R : X -> X -> Prop} x y z : R y z -> clos_trans_1n _ R x y -> clos_trans_1n _ R x z.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	clos_trans_1n_right	null
clos_trans_n1_1n {R : X -> X -> Prop} x y : clos_trans_n1 _ R x y -> clos_trans_1n _ R x y.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	clos_trans_n1_1n	null
acc_from_af (p : WFT X) (T R : X → X → Prop) y : (∀ x z, clos_refl_trans X T z y -> clos_trans_1n X T x z ∧ R z x → False) → SecureBy R p → Acc T y.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	acc_from_af	null
wf_from_af (p : WFT X) (T R : X → X → Prop) : (∀ x y, clos_trans_1n X T x y ∧ R y x → False) → SecureBy R p → well_founded T.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	wf_from_af	null
compose_rel {X} (R S : X -> X -> Prop) : relation X := fun x y => exists z, R x z /\ S z y.	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	compose_rel	null
power (k : nat) (T : X -> X -> Prop) : X -> X -> Prop := power 0 T := T; power (S k) T := fun x y => exists z, power k T x z /\ T z y.	Equations	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	power	null
acc_incl (T T' : X -> X -> Prop) x : (forall x y, T' x y -> T x y) -> Acc T x -> Acc T' x.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	acc_incl	null
power_clos_trans (T : X -> X -> Prop) k : inclusion _ (power k T) (clos_trans _ T).	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	power_clos_trans	null
clos_trans_power (T : X -> X -> Prop) x y : clos_trans _ T x y -> exists k, power k T x y.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	clos_trans_power	null
acc_power (T : X -> X -> Prop) x k : Acc T x -> Acc (power k T) x.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	acc_power	null
secure_power (k : nat) (p : WFT X) : WFT X := secure_power 0 p := p; secure_power (S k) p := SUP (fun x => secure_power k p).	Equations	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	secure_power	null
secure_by_power R p (H : SecureBy R p) k : SecureBy R (secure_power k p).	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	secure_by_power	null
acc_from_power_af (p : WFT X) (T R : X → X → Prop) y k : (∀ x z, clos_refl_trans _ T z y -> clos_trans_1n X (power k T) x z ∧ R z x → False) → SecureBy R (secure_power k p) → Acc T y.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	acc_from_power_af	null
wf_from_power_af (p : WFT X) (T R : X → X → Prop) k : (∀ x y, clos_trans_1n X (power k T) x y ∧ R y x → False) → SecureBy R p → well_founded T.	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	wf_from_power_af	null
af_wf : WellFounded T.	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	af_wf	null
af_power_wf : WellFounded T.	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	af_power_wf	null
cofmap {X Y : Type} (f : Y -> X) (p : WFT X) : WFT Y := cofmap f ZT := ZT; cofmap f (SUP w) := SUP (fun y => cofmap f (w (f y))).	Equations	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	cofmap	null
cofmap_secures {X Y : Type} (f : Y -> X) (p : WFT X) (R : X -> X -> Prop) : SecureBy R p -> SecureBy (fun x y => R (f x) (f y)) (cofmap f p).	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	cofmap_secures	null
#[export] Instance AlmostFull_MR {X Y} R (f : Y -> X) : AlmostFull R -> AlmostFull (Wf.MR R f).	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	AlmostFull_MR	null
oplus_nullary {X:Type} (p:WFT X) (q:WFT X) := match p with \| ZT => q \| SUP f => SUP (fun x => oplus_nullary (f x) q) end.	Fixpoint	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	oplus_nullary	null
oplus_nullary_sec_intersection {X} (p : WFT X) (q: WFT X) (C : X → X → Prop) (A : Prop) (B : Prop) : SecureBy (fun y z => C y z ∨ A) p → SecureBy (fun y z => C y z ∨ B) q → SecureBy (fun y z => C y z ∨ (A ∧ B)) (oplus_nullary p q).	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	oplus_nullary_sec_intersection	null
oplus_unary_sec_intersection {X} (p q : WFT X) (C : X -> X -> Prop) (A B : X -> Prop) : SecureBy (fun y z => C y z \/ A y) p -> SecureBy (fun y z => C y z \/ B y) q -> SecureBy (fun y z => C y z \/ (A y /\ B y)) (oplus_unary p q).	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	oplus_unary_sec_intersection	null
oplus_binary_sec_intersection' {X} (p q : WFT X) (C : X -> X -> Prop) (A B : X -> X -> Prop) : SecureBy (fun y z => C y z \/ A y z) p -> SecureBy (fun y z => C y z \/ B y z) q -> SecureBy (fun y z => C y z \/ (A y z /\ B y z)) (oplus_binary p q).	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	oplus_binary_sec_intersection	null
oplus_binary_sec_intersection {X} (p q : WFT X) (A B : X -> X -> Prop) : SecureBy A p -> SecureBy B q -> SecureBy (fun y z => A y z /\ B y z) (oplus_binary p q).	Lemma	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	oplus_binary_sec_intersection	null
inter_rel {X : Type} (A B : X -> X -> Prop) := fun x y => A x y /\ B x y.	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	inter_rel	null
af_interesection {X : Type} (A B : X -> X -> Prop) : AlmostFull A -> AlmostFull B -> AlmostFull (inter_rel A B).	Corollary	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	af_interesection	null
af_bool : AlmostFull (@eq bool).	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	af_bool	null
product_rel {X Y : Type} (A : X -> X -> Prop) (B : Y -> Y -> Prop) := fun x y => A (fst x) (fst y) /\ B (snd x) (snd y).	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	product_rel	null
#[export] Instance af_product {X Y : Type} (A : X -> X -> Prop) (B : Y -> Y -> Prop) : AlmostFull A -> AlmostFull B -> AlmostFull (product_rel A B).	Instance	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	af_product	null
T (x y : nat * nat) : Prop := (fst x = snd y /\ snd x < snd y) \/ (fst x = snd y /\ snd x < fst y).	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	T	null
Tl (x y : nat * (nat * unit)) : Prop := (fst x = fst (snd y) /\ fst (snd x) < fst (snd y)).	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	Tl	null
Tr (x y : nat * (nat * unit)) : Prop := (fst x = fst (snd y) /\ fst (snd x) < fst y).	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	Tr	null
subgraph k k' := fin k -> option (bool * fin k').	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	subgraph	null
graph k := subgraph k k.	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	graph	null
strict {k} (f : fin k) := Some (true, f).	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	strict	null
large {k} (f : fin k) := Some (false, f).	Definition	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	large	null
T_graph_l (x : fin 2) : option (bool * fin 2) := { T_graph_l fz := large (fs fz); T_graph_l (fs fz) := strict (fs fz) }.	Equations	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	T_graph_l	null
T_graph_r (x : fin 2) : option (bool * fin 2) := { T_graph_r fz := large (fs fz); T_graph_r (fs fz) := strict fz }.	Equations	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	T_graph_r	null
graph_compose {k} (g1 g2 : graph k) : graph k := graph_compose g1 g2 arg0 with g1 arg0 := { \| Some (weight, arg1) with g2 arg1 := { \| Some (weight', arg2) => Some (weight \|\| weight', arg2); \| None => None }; \| None => None }.	Equations	examples	[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]	examples/AlmostFull.v	graph_compose	null

bool : Set := true : bool | false : bool ]] We can define the boolean negation as follows: *) Equations neg (b : bool) : bool := neg true := false; neg false := true.

Inductive

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

bool

null

neg (b : bool) : bool := neg true := false; neg false := true.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

neg

* Inductive types In its simplest form, [Equations] allows to define functions on inductive datatypes. Take for example the booleans defined as an inductive type with two constructors [true] and [false]: [[ Inductive bool : Set := true : bool | false : bool ]] We can define the boolean negation as follows:

neg_inv : forall b, neg (neg b) = b.

Lemma

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

neg_inv

null

neg_ind : bool -> bool -> Prop := | neg_ind_equation_1 : neg_ind true false | neg_ind_equation_2 : neg_ind false true ]] Along with a proof of [Π b, neg_ind b (neg b)], we can eliminate any call to [neg] specializing its argument and result in a single command.

Inductive

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

neg_ind

null

list {A} : Type := nil : list | cons : A -> list -> list.

Inductive

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

list

* Reasoning principles In the setting of a proof assistant like Coq, we need not only the ability to define complex functions but also get good reasoning support for them. Practically, this translates to the ability to simplify applications of functions appearing in the goal and to give strong enough proof principles for (recursive) definitions. [Equations] provides this through an automatic generation of proofs related to the function. Namely, each defining equation gives rise to a lemma stating the equality between the left and right hand sides. These equations can be used as rewrite rules for simplification during proofs, without having to rely on the fragile simplifications implemented by raw reduction. We can also generate the inductive graph of any [Equations] definition, giving the strongest elimination principle on the function. I.e., for [neg] the inductive graph is defined as: [[ Inductive neg_ind : bool -> bool -> Prop := | neg_ind_equation_1 : neg_ind true false | neg_ind_equation_2 : neg_ind false true ]] Along with a proof of [Π b, neg_ind b (neg b)], we can eliminate any call to [neg] specializing its argument and result in a single command. Suppose we want to show that [neg] is involutive for example, our goal will look like: [[ b : bool ============================ neg (neg b) = b ]] An application of the tactic [funelim (neg b)] will produce two goals corresponding to the splitting done in [neg]: [neg false = true] and [neg true = false]. These correspond exactly to the rewriting lemmas generated for [neg]. In the following sections we will show how these ideas generalize to more complex types and definitions involving dependencies, overlapping clauses and recursion. * Building up ** Polymorphism Coq's inductive types can be parameterized by types, giving polymorphic datatypes. For example the list datatype is defined as:

tail {A} (l : list A) : list A := tail nil := nil ; tail (cons a v) := v.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

tail

No special support for polymorphism is needed, as type arguments are treated like regular arguments in dependent type theories. Note however that one cannot match on type arguments, there is no intensional type analysis. We can write the polymorphic [tail] function as follows:

app {A} (l l' : list A) : list A := app nil l' := l' ; app (cons a l) l' := cons a (app l l').

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

app

** Recursive inductive types Of course with inductive types comes recursion. Coq accepts a subset of the structurally recursive definitions by default (it is incomplete due to its syntactic nature). We will use this as a first step towards a more robust treatment of recursion via well-founded relations. A classical example is list concatenation:

filter {A} (l : list A) (p : A -> bool) : list A := filter nil p := nil ; filter (cons a l) p with p a => { filter (cons a l) p true := a :: filter l p ; filter (cons a l) p false := filter l p }.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

filter

** Moving to the left The structure of real programs is richer than a simple case tree on the original arguments in general. In the course of a computation, we might want to scrutinize intermediate results (e.g. coming from function calls) to produce an answer. This literally means adding a new pattern to the left of our equations made available for further refinement. This concept is know as with clauses in the Agda %\cite{norell:thesis}% community and was first presented and implemented in the Epigram language %\cite{DBLP:journals/jfp/McBrideM04}%. The compilation of with clauses and its treatment for generating equations and the induction principle are quite involved in the presence of dependencies, but the basic idea is to add a new case analysis to the program. To compute the type of the new subprogram, we actually abstract the discriminee term from the expected type of the clause, so that the type can get refined in the subprogram. In the non-dependent case this does not change anything though. Each [with] node generates an auxiliary definition from the clauses in the curly brackets, taking the additional object as argument. The equation for the with node will simply be an indirection to the auxiliary definition and simplification will continue as usual with the auxiliary definition's rewrite rules.

filter' {A} (l : list A) (p : A -> bool) : list A := | [], p => [] | a :: l, p with p a => { | true => a :: filter' l p | false => filter' l p }.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

filter

A more compact syntax can be used to avoid repeating the same patterns in multiple clauses and focus on the patterns that matter. When a clause starts with `|`, a list of patterns separated by "," or "|" can be provided in open syntax, without parentheses. They should match the explicit arguments of the current problem. Under a `with` node, they should match the variable(s) introduced by the `with` construct. When using "|", the ";" at the end of a clause becomes optional.

unzip {A B} (l : list (A * B)) : list A * list B := unzip nil := (nil, nil) ; unzip (cons p l) with unzip l => { unzip (cons (pair a b) l) (pair la lb) := (a :: la, b :: lb) }.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

unzip

A common use of with clauses is to scrutinize recursive results like the following:

equal (n m : nat) : { n = m } + { n <> m } := equal O O := left eq_refl ; equal (S n) (S m) with equal n m := { equal (S n) (S ?(n)) (left eq_refl) := left eq_refl ; equal (S n) (S m) (right p) := right _ } ; equal x y := right _.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

equal

* Dependent types Coq supports writing dependent functions, in other words, it gives the ability to make the results _type_ depend on actual _values_, like the arguments of the function. A simple example is given below of a function which decides the equality of two natural numbers, returning a sum type carrying proofs of the equality or disequality of the arguments. The sum type [{ A } + { B }] is a constructive variant of disjunction that can be used in programs to give at the same time a boolean algorithmic information (are we in branch [A] or [B]) and a _logical_ information (a proof witness of [A] or [B]). Hence its constructors [left] and [right] take proofs as arguments. The [eq_refl] proof term is the single proof of [x = x] (the [x] is generaly infered automatically).

head {A} (l : list A) (pf : l <> nil) : A := head nil pf with pf eq_refl := { | ! }; head (cons a v) _ := a.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

head

Of particular interest here is the inner program refining the recursive result. As [equal n m] is of type [{ n = m } + { n <> m }] we have two cases to consider: - Either we are in the [left p] case, and we know that [p] is a proof of [n = m], in which case we can do a nested match on [p]. The result of matching this equality proof is to unify [n] and [m], hence the left hand side patterns become [S n] and [S ?(n)] and the return type of this branch is refined to [{ n = n } + { n <> n }]. We can easily provide a proof for the left case. - In the right case, we mark the proof unfilled with an underscore. This will generate an obligation for the hole, that can be filled automatically by a predefined tactic or interactively by the user in proof mode (this uses the same obligation mechanism as the Program extension %\cite{sozeau.Coq/FingerTrees/article}%). In this case the automatic tactic is able to derive by itself that [n <> m -> S n <> S m]. Dependent types are also useful to turn partial functions into total functions by restricting their domain. Typically, we can force the list passed to [head] to be non-empty using the specification:

eq (A : Type) (x : A) : A -> Prop := eq_refl : eq A x x.

Inductive

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

eq

null

eqt {A} (x y z : A) (p : x = y) (q : y = z) : x = z := eqt x ?(x) ?(x) eq_refl eq_refl := eq_refl.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

eqt

** Inductive families The next step is to make constraints such as non-emptiness part of the datatype itself. This capability is provided through inductive families in Coq %\cite{paulin93tlca}%, which are a similar concept to the generalization of algebraic datatypes to GADTs in functional languages like Haskell %\cite{GADTcomplete}%. Families provide a way to associate to each constructor a different type, making it possible to give specific information about a value in its type. *** Equality The alma mater of inductive families is the propositional equality [eq] defined as: [[ Inductive eq (A : Type) (x : A) : A -> Prop := eq_refl : eq A x x. ]] Equality is a polymorphic relation on [A]. (The [Prop] sort (or kind) categorizes propositions, while the [Set] sort, equivalent to $\star$ in Haskell categorizes computational types.) Equality is _parameterized_ by a value [x] of type [A] and _indexed_ by another value of type [A]. Its single constructor states that equality is reflexive, so the only way to build an object of [eq x y] is if [x ~= y], that is if [x] is definitionaly equal to [y]. Now what is the elimination principle associated to this inductive family? It is the good old Leibniz substitution principle: [[ forall (A : Type) (x : A) (P : A -> Type), P x -> forall y : A, x = y -> P y ]] Provided a proof that [x = y], we can create on object of type [P y] from an existing object of type [P x]. This substitution principle is enough to show that equality is symmetric and transitive. For example we can use pattern-matching on equality proofs to show:

vmap {A B} (f : A -> B) {n} (v : vector A n) : vector B n := vmap f (n:=?(0)) Vnil := Vnil ; vmap f (Vcons a v) := Vcons (f a) (vmap f v).

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

vmap

null

vtail {A n} (v : vector A (S n)) : vector A n := vtail (Vcons a v') := v'.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

vtail

Here the value of the index representing the size of the vector is directly determined by the constructor, hence in the case tree we have no need to eliminate [n]. This means in particular that the function [vmap] does not do any computation with [n], and the argument could be eliminated in the extracted code. In other words, it provides only _logical_ information about the shape of [v] but no computational information. The [vmap] function works on every member of the [vector] family, but some functions may work only for some subfamilies, for example [vtail]:

NoConfusion for nat.

Derive

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

NoConfusion

** Derived notions, No-Confusion For this to work smoothlty, the package requires some derived definitions on each (indexed) family, which can be generated automatically using the generic [Derive] command. Here we ask to generate the signature, heterogeneous no-confusion and homogeneous no-confusion principles for vectors:

Signature NoConfusion NoConfusionHom for vector.

Derive

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

Signature

null

diag {A n} (v : vector (vector A n) n) : vector A n := diag (n:=O) Vnil := Vnil ; diag (n:=S _) (Vcons (Vcons a v) v') := Vcons a (diag (vmap vtail v')).

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

diag

The precise specification of these derived definitions can be found in the manual section %(\S \ref{manual})%. Signature is used to "pack" a value in an inductive family with its index, e.g. the "total space" of every index and value of the family. This can be used to derive the heterogeneous no-confusion principle for the family, which allows to discriminate between objects in potentially different instances/fibers of the family, or deduce injectivity of each constructor. The [NoConfusionHom] variant derives the homogeneous no-confusion principle between two objects in the _same_ instance of the family, e.g. to simplify equations of the form [Vnil = Vnil :> vector A 0]. This last principle can only be defined when pattern-matching on the inductive family does not require the [K] axiom and will otherwise fail. ** Unification and indexed datatypes Back to our example, of course the equations and the induction principle are simplified in a similar way. If we encounter a call to [vtail] in a proof, we can use the following elimination principle to simplify both the call and the argument which will be automatically substituted by an object of the form [Vcons _ _ _]:[[ forall P : forall (A : Type) (n : nat), vector A (S n) -> vector A n -> Prop, (forall (A : Type) (n : nat) (a : A) (v : vector A n), P A n (Vcons a v) v) -> forall (A : Type) (n : nat) (v : vector A (S n)), P A n v (vtail v) ]] As a witness of the power of the unification, consider the following function which computes the diagonal of a square matrix of size [n * n].

id (n : nat) : nat by wf n lt := id 0 := 0; id (S n') := S (id n').

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

id

Indeed, Coq cannot guess the decreasing argument of this fixpoint using its limited syntactic guard criterion: [vmap vtail v'] cannot be seen to be a (large) subterm of [v'] using this criterion, even if it is clearly "smaller". In general, it can also be the case that the compilation algorithm introduces decorations to the proof term that prevent the syntactic guard check from seeing that the definition is structurally recursive. To aleviate this problem, [Equations] provides support for _well-founded_ recursive definitions which do not rely on syntactic checks. The simplest example of this is using the [lt] order on natural numbers to define a recursive definition of identity:

Subterm for vector.

Derive

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

Subterm

Here [id] is defined by well-founded recursion on [lt] on the (only) argument [n] using the [by wf] annotation. At recursive calls of [id], obligations are generated to show that the arguments effectively decrease according to this relation. Here the proof that [n' < S n'] is discharged automatically. Wellfounded recursion on arbitrary dependent families is not as easy to use, as in general the relations on families are _heterogeneous_, as they must relate inhabitants of potentially different instances of the family. [Equations] provides a [Derive] command to generate the subterm relation on any such inductive family and derive the well-foundedness of its transitive closure. This provides course-of-values or so-called "mathematical" induction on these objects, reflecting the structural recursion criterion in the logic.

t_direct_subterm (A : Type) : forall n n0 : nat, vector A n -> vector A n0 -> Prop := t_direct_subterm_1_1 : forall (h : A) (n : nat) (H : vector A n), t_direct_subterm A n (S n) H (Vcons h H) ]] That is, there is only one recursive subterm, for the subvector in the [Vcons] constructor.

Inductive

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

t_direct_subterm

null

unzip {n} (v : vector (A * B) n) : vector A n * vector B n by wf (signature_pack v) (@t_subterm (A * B)) := unzip Vnil := (Vnil, Vnil) ; unzip (Vector.cons (pair x y) v) with unzip v := { | pair xs ys := (Vector.cons x xs, Vector.cons y ys) }.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

unzip

We can use the packed relation to do well-founded recursion on the vector. Note that we do a recursive call on a substerm of type [vector A n] which must be shown smaller than a [vector A (S n)]. They are actually compared at the packed type [{ n : nat & vector A n}]. The default obligation tactic defined in [Equations.Init] includes a proof-search for [subterm] proofs which can resolve the recursive call obligation automatically in this case.

diag' {A n} (v : vector (vector A n) n) : vector A n by wf n := diag' Vnil := Vnil ; diag' (Vcons (Vcons a v) v') := Vcons a (diag' (vmap vtail v')).

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

diag

For the diagonal, it is easier to give [n] as the decreasing argument of the function, even if the pattern-matching itself is on vectors:

uipa : forall A, UIP A.

Axiom

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

uipa

The user must declare this axiom itself, as an instance of the [UIP] class.

Instance uipa.

Existing

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

Instance

null

K {A} (x : A) (P : x = x -> Type) (p : P eq_refl) (H : x = x) : P H := K x P p eq_refl := p.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

K

In this case the following definition uses the [UIP] axiom just declared.

allows however to use constructive proofs of UIP for types enjoying decidable equality.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

allows

null

K' (x : nat) (P : x = x -> Type) (p : P eq_refl) (H : x = x) : P H := K' x P p eq_refl := p.

Equations

doc

[ "Coq.Arith", "Coq.Lia", "Coq.Program", "Equations.Equations", "Bvector" ]

doc/equations_intro.v

K

Note that the definition loses its computational content: it will get stuck on an axiom. We hence do not recommend its use. Equations allows however to use constructive proofs of UIP for types enjoying decidable equality. The following example relies on an instance of the [EqDec] typeclass for natural numbers, from which we can automatically derive a [UIP nat] instance. Note that the computational behavior of this definition on open terms is not to reduce to [p] but pattern-matches on the decidable equality proof. However the defining equation still holds as a _propositional_ equality, and the definition of K' is axiom-free.

rev_acc {A} (l : list A) : list A := rev_acc l := go [] l where go : list A -> list A -> list A := go acc [] := acc; go acc (hd :: tl) := go (hd :: acc) tl.

Equations

examples

[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]

examples/accumulator.v

rev_acc

** Worker/wrapper The most standard example is an efficient implementation of list reversal. Instead of growing the stack by the size of the list, we accumulate a partially reverted list as a new argument of our function. We implement this using a [go] auxilliary function defined recursively and pattern matching on the list.

rev_acc_eq : forall {A} (l : list A), rev_acc l = rev l.

Lemma

examples

[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]

examples/accumulator.v

rev_acc_eq

A typical issue with such accumulating functions is that one has to write lemmas in two versions, once about the internal [go] function and then on its wrapper. Using the functional elimination principle associated to [rev_acc], we can show both properties simultaneously.

indexes : list nat -> list nat := indexes l := go [] (length l) where go : list nat -> nat -> list nat := go acc 0 := acc; go acc (S n) := go (n :: acc) n.

Equations

examples

[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]

examples/accumulator.v

indexes

** Programm equivalence with worker/wrappers Finally we show how the eliminator can be used to prove program equivalences involving a worker/wrapper definition. Here [indexes l] computes the list [0..|l|-1] of valid indexes in the list [l].

indexes_spec (l : list nat) : Forall (fun x => x < length l) (indexes l).

Lemma

examples

[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]

examples/accumulator.v

indexes_spec

Clearly, all indexes in the resulting list should be smaller than [length l]:

interval_large x y : ~ x < y -> interval x y = [].

Lemma

examples

[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]

examples/accumulator.v

interval_large

We prove a simple lemmas on [interval]:

indexes_interval l : indexes l = interval 0 (length l).

Lemma

examples

[ "Equations.Equations", "Coq.List", "Coq.Program", "ExtrOcamlBasic" ]

examples/accumulator.v

indexes_interval

One can show that [indexes l] produces the interval [0..|l|-1] using [indexes_elim]. The recursion invariant for [indexes_go] records that [acc] corresponds to a partial interval [n..|l|-1] during the computation, and is finally completed into [0..|l|-1] by the end of the computation. We use the previous lemmas as helpers.

Eq (A : Type) := { eqb : A -> A -> bool; eqb_spec : forall x y, reflect (x = y) (eqb x y) }.

Class

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

Eq

null

fin_eq {k} (f f' : fin k) : bool := fin_eq fz fz => true; fin_eq (fs f) (fs f') => fin_eq f f'; fin_eq _ _ => false.

Equations

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

fin_eq

null

fin_Eq k : Eq (fin k).

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

fin_Eq

null

bool_Eq : Eq bool.

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

bool_Eq

null

prod_eq A B : Eq A -> Eq B -> Eq (A * B).

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

prod_eq

null

option_eq {A : Type} {E:Eq A} (o o' : option A) : bool := option_eq None None := true; option_eq (Some o) (Some o') := eqb o o'; option_eq _ _ := false.

Equations

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

option_eq

null

option_Eq A : Eq A -> Eq (option A).

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

option_Eq

null

eq_fin_fn {k} (f g : fin k -> A) : bool := eq_fin_fn (k:=0) f g := true; eq_fin_fn (k:=S k) f g := eqb (f fz) (g fz) && eq_fin_fn (fun n => f (fs n)) (fun n => g (fs n)).

Equations

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

eq_fin_fn

null

Eq_graph k : Eq (fin k -> A).

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

Eq_graph

null

dec_rel {X:Type} (R : X → X → Prop) := ∀ x y, {R x y} + {not (R x y)}.

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

dec_rel

null

WFT : Type := | ZT : WFT | SUP : (X -> WFT) -> WFT.

Inductive

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

WFT

null

NoConfusion Subterm for WFT.

Derive

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

NoConfusion

null

sec_disj (R : X -> X -> Prop) x y z := R y z \/ R x y.

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

sec_disj

null

SecureBy (R : X -> X -> Prop) (p : WFT) : Prop := match p with | ZT => forall x y, R x y | SUP f => forall x, SecureBy (fun y z => R y z \/ R x y) (f x) end.

Fixpoint

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

SecureBy

null

SecureBy_mon p (R' S : X -> X -> Prop) (H : forall x y, R' x y -> S x y) : SecureBy R' p -> SecureBy S p.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

SecureBy_mon

null

almost_full (R : X -> X -> Prop) := exists p, SecureBy R p.

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

almost_full

null

af_tree_iter {x : X} (accX : Acc R x) := match accX with | Acc_intro f => SUP (fun y => match decR y x with | left Ry => af_tree_iter (f y Ry) | right _ => ZT end) end.

Fixpoint

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

af_tree_iter

null

af_tree : X → WFT := fun x => af_tree_iter (wfR x).

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

af_tree

null

secure_from_wf : SecureBy (fun x y => not (R y x)) (SUP af_tree).

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

secure_from_wf

null

af_from_wf : almost_full (fun x y => not (R y x)).

Corollary

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

af_from_wf

null

AlmostFull {X} (R : X -> X -> Prop) := is_almost_full : almost_full R.

Class

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

AlmostFull

null

#[export] Instance proper_af X : Proper (relation_equivalence ==> iff) (@AlmostFull X).

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

proper_af

null

#[export] Instance almost_full_le : AlmostFull Peano.le.

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

almost_full_le

null

clos_trans_n1_left {R : X -> X -> Prop} x y z : R x y -> clos_trans_n1 _ R y z -> clos_trans_n1 _ R x z.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

clos_trans_n1_left

null

clos_trans_1n_n1 {R : X -> X -> Prop} x y : clos_trans_1n _ R x y -> clos_trans_n1 _ R x y.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

clos_trans_1n_n1

null

clos_refl_trans_right {R : X -> X -> Prop} x y z : R y z -> clos_refl_trans _ R x y -> clos_trans_n1 _ R x z.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

clos_refl_trans_right

null

clos_trans_1n_right {R : X -> X -> Prop} x y z : R y z -> clos_trans_1n _ R x y -> clos_trans_1n _ R x z.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

clos_trans_1n_right

null

clos_trans_n1_1n {R : X -> X -> Prop} x y : clos_trans_n1 _ R x y -> clos_trans_1n _ R x y.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

clos_trans_n1_1n

null

acc_from_af (p : WFT X) (T R : X → X → Prop) y : (∀ x z, clos_refl_trans X T z y -> clos_trans_1n X T x z ∧ R z x → False) → SecureBy R p → Acc T y.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

acc_from_af

null

wf_from_af (p : WFT X) (T R : X → X → Prop) : (∀ x y, clos_trans_1n X T x y ∧ R y x → False) → SecureBy R p → well_founded T.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

wf_from_af

null

compose_rel {X} (R S : X -> X -> Prop) : relation X := fun x y => exists z, R x z /\ S z y.

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

compose_rel

null

power (k : nat) (T : X -> X -> Prop) : X -> X -> Prop := power 0 T := T; power (S k) T := fun x y => exists z, power k T x z /\ T z y.

Equations

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

power

null

acc_incl (T T' : X -> X -> Prop) x : (forall x y, T' x y -> T x y) -> Acc T x -> Acc T' x.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

acc_incl

null

power_clos_trans (T : X -> X -> Prop) k : inclusion _ (power k T) (clos_trans _ T).

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

power_clos_trans

null

clos_trans_power (T : X -> X -> Prop) x y : clos_trans _ T x y -> exists k, power k T x y.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

clos_trans_power

null

acc_power (T : X -> X -> Prop) x k : Acc T x -> Acc (power k T) x.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

acc_power

null

secure_power (k : nat) (p : WFT X) : WFT X := secure_power 0 p := p; secure_power (S k) p := SUP (fun x => secure_power k p).

Equations

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

secure_power

null

secure_by_power R p (H : SecureBy R p) k : SecureBy R (secure_power k p).

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

secure_by_power

null

acc_from_power_af (p : WFT X) (T R : X → X → Prop) y k : (∀ x z, clos_refl_trans _ T z y -> clos_trans_1n X (power k T) x z ∧ R z x → False) → SecureBy R (secure_power k p) → Acc T y.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

acc_from_power_af

null

wf_from_power_af (p : WFT X) (T R : X → X → Prop) k : (∀ x y, clos_trans_1n X (power k T) x y ∧ R y x → False) → SecureBy R p → well_founded T.

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

wf_from_power_af

null

af_wf : WellFounded T.

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

af_wf

null

af_power_wf : WellFounded T.

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

af_power_wf

null

cofmap {X Y : Type} (f : Y -> X) (p : WFT X) : WFT Y := cofmap f ZT := ZT; cofmap f (SUP w) := SUP (fun y => cofmap f (w (f y))).

Equations

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

cofmap

null

cofmap_secures {X Y : Type} (f : Y -> X) (p : WFT X) (R : X -> X -> Prop) : SecureBy R p -> SecureBy (fun x y => R (f x) (f y)) (cofmap f p).

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

cofmap_secures

null

#[export] Instance AlmostFull_MR {X Y} R (f : Y -> X) : AlmostFull R -> AlmostFull (Wf.MR R f).

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

AlmostFull_MR

null

oplus_nullary {X:Type} (p:WFT X) (q:WFT X) := match p with | ZT => q | SUP f => SUP (fun x => oplus_nullary (f x) q) end.

Fixpoint

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

oplus_nullary

null

oplus_nullary_sec_intersection {X} (p : WFT X) (q: WFT X) (C : X → X → Prop) (A : Prop) (B : Prop) : SecureBy (fun y z => C y z ∨ A) p → SecureBy (fun y z => C y z ∨ B) q → SecureBy (fun y z => C y z ∨ (A ∧ B)) (oplus_nullary p q).

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

oplus_nullary_sec_intersection

null

oplus_unary_sec_intersection {X} (p q : WFT X) (C : X -> X -> Prop) (A B : X -> Prop) : SecureBy (fun y z => C y z \/ A y) p -> SecureBy (fun y z => C y z \/ B y) q -> SecureBy (fun y z => C y z \/ (A y /\ B y)) (oplus_unary p q).

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

oplus_unary_sec_intersection

null

oplus_binary_sec_intersection' {X} (p q : WFT X) (C : X -> X -> Prop) (A B : X -> X -> Prop) : SecureBy (fun y z => C y z \/ A y z) p -> SecureBy (fun y z => C y z \/ B y z) q -> SecureBy (fun y z => C y z \/ (A y z /\ B y z)) (oplus_binary p q).

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

oplus_binary_sec_intersection

null

oplus_binary_sec_intersection {X} (p q : WFT X) (A B : X -> X -> Prop) : SecureBy A p -> SecureBy B q -> SecureBy (fun y z => A y z /\ B y z) (oplus_binary p q).

Lemma

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

oplus_binary_sec_intersection

null

inter_rel {X : Type} (A B : X -> X -> Prop) := fun x y => A x y /\ B x y.

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

inter_rel

null

af_interesection {X : Type} (A B : X -> X -> Prop) : AlmostFull A -> AlmostFull B -> AlmostFull (inter_rel A B).

Corollary

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

af_interesection

null

af_bool : AlmostFull (@eq bool).

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

af_bool

null

product_rel {X Y : Type} (A : X -> X -> Prop) (B : Y -> Y -> Prop) := fun x y => A (fst x) (fst y) /\ B (snd x) (snd y).

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

product_rel

null

#[export] Instance af_product {X Y : Type} (A : X -> X -> Prop) (B : Y -> Y -> Prop) : AlmostFull A -> AlmostFull B -> AlmostFull (product_rel A B).

Instance

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

af_product

null

T (x y : nat * nat) : Prop := (fst x = snd y /\ snd x < snd y) \/ (fst x = snd y /\ snd x < fst y).

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

T

null

Tl (x y : nat * (nat * unit)) : Prop := (fst x = fst (snd y) /\ fst (snd x) < fst (snd y)).

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

Tl

null

Tr (x y : nat * (nat * unit)) : Prop := (fst x = fst (snd y) /\ fst (snd x) < fst y).

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

Tr

null

subgraph k k' := fin k -> option (bool * fin k').

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

subgraph

null

graph k := subgraph k k.

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

graph

null

strict {k} (f : fin k) := Some (true, f).

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

strict

null

large {k} (f : fin k) := Some (false, f).

Definition

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

large

null

T_graph_l (x : fin 2) : option (bool * fin 2) := { T_graph_l fz := large (fs fz); T_graph_l (fs fz) := strict (fs fz) }.

Equations

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

T_graph_l

null

T_graph_r (x : fin 2) : option (bool * fin 2) := { T_graph_r fz := large (fs fz); T_graph_r (fs fz) := strict fz }.

Equations

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

T_graph_r

null

graph_compose {k} (g1 g2 : graph k) : graph k := graph_compose g1 g2 arg0 with g1 arg0 := { | Some (weight, arg1) with g2 arg1 := { | Some (weight', arg2) => Some (weight || weight', arg2); | None => None }; | None => None }.

Equations

examples

[ "Equations.Equations", "Examples", "Relations", "Utf8", "Relations", "Wellfounded", "Setoid", "RelationClasses", "Morphisms", "Lia", "Bool", "List", "Arith", "String", "Coq.FunctionalExtensionality", "ssreflect", "Lia", "ExtrOcamlBasic" ]

examples/AlmostFull.v

graph_compose

null

Type	Count
Lemma	834
Equations	735
Definition	518
Inductive	300
Derive	234
Instance	129
Theorem	58
Fixpoint	57
Class	55
Other	175

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phanerozoic
/

Coq-Equations

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Collection including phanerozoic/Coq-Equations

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Column	Type	Description
fact	string	Full declaration (name, signature, body)
type	string	Equations, Lemma, Definition, Derive, etc.
library	string	Component (theories, examples, test-suite, doc)
imports	list	Import statements
filename	string	Source file path
symbolic_name	string	Declaration identifier
docstring	string	Documentation comment (14% coverage)