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equivToOpposite_symm_coe : (equivToOpposite.symm : αᵒᵖ → α) = unop := rfl
theorem
Data
[ "Mathlib.Logic.Equiv.Defs", "Mathlib.Logic.Small.Defs" ]
Mathlib/Data/Opposite.lean
equivToOpposite_symm_coe
null
op_eq_iff_eq_unop {x : α} {y} : op x = y ↔ x = unop y := equivToOpposite.apply_eq_iff_eq_symm_apply
theorem
Data
[ "Mathlib.Logic.Equiv.Defs", "Mathlib.Logic.Small.Defs" ]
Mathlib/Data/Opposite.lean
op_eq_iff_eq_unop
null
unop_eq_iff_eq_op {x} {y : α} : unop x = y ↔ x = op y := equivToOpposite.symm.apply_eq_iff_eq_symm_apply
theorem
Data
[ "Mathlib.Logic.Equiv.Defs", "Mathlib.Logic.Small.Defs" ]
Mathlib/Data/Opposite.lean
unop_eq_iff_eq_op
null
@[deprecated Opposite.rec (since := "2025-04-04")] protected rec' {F : αᵒᵖ → Sort v} (h : ∀ X, F (op X)) : ∀ X, F X := fun X => h (unop X)
def
Data
[ "Mathlib.Logic.Equiv.Defs", "Mathlib.Logic.Small.Defs" ]
Mathlib/Data/Opposite.lean
rec'
A deprecated alias for `Opposite.rec`.
small {X : Type v} [Small.{u} X] : Small.{u} Xᵒᵖ := by obtain ⟨S, ⟨e⟩⟩ := Small.equiv_small (α := X) exact ⟨S, ⟨equivToOpposite.symm.trans e⟩⟩
lemma
Data
[ "Mathlib.Logic.Equiv.Defs", "Mathlib.Logic.Small.Defs" ]
Mathlib/Data/Opposite.lean
small
If `X` is `u`-small, also `Xᵒᵖ` is `u`-small. Note: This is not an instance, because it tends to mislead typeclass search.
Part.{u} (α : Type u) : Type u where /-- The domain of a partial value -/ Dom : Prop /-- Extract a value from a partial value given a proof of `Dom` -/ get : Dom → α
structure
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
Part.
`Part α` is the type of "partial values" of type `α`. It is similar to `Option α` except the domain condition can be an arbitrary proposition, not necessarily decidable.
toOption (o : Part α) [Decidable o.Dom] : Option α := if h : Dom o then some (o.get h) else none @[simp] lemma toOption_isSome (o : Part α) [Decidable o.Dom] : o.toOption.isSome ↔ o.Dom := by by_cases h : o.Dom <;> simp [h, toOption] @[simp] lemma toOption_eq_none (o : Part α) [Decidable o.Dom] : o.toOption = none ↔ ¬o.Dom := by by_cases h : o.Dom <;> simp [h, toOption]
def
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
toOption
Convert a `Part α` with a decidable domain to an option
ext' : ∀ {o p : Part α}, (o.Dom ↔ p.Dom) → (∀ h₁ h₂, o.get h₁ = p.get h₂) → o = p | ⟨od, o⟩, ⟨pd, p⟩, H1, H2 => by have t : od = pd := propext H1 cases t; rw [show o = p from funext fun p => H2 p p]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
ext'
`Part` extensionality
@[simp] eta : ∀ o : Part α, (⟨o.Dom, fun h => o.get h⟩ : Part α) = o | ⟨_, _⟩ => rfl
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
eta
`Part` eta expansion
protected Mem (o : Part α) (a : α) : Prop := ∃ h, o.get h = a
def
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
Mem
`a ∈ o` means that `o` is defined and equal to `a`
mem_eq (a : α) (o : Part α) : (a ∈ o) = ∃ h, o.get h = a := rfl
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_eq
null
dom_iff_mem : ∀ {o : Part α}, o.Dom ↔ ∃ y, y ∈ o | ⟨_, f⟩ => ⟨fun h => ⟨f h, h, rfl⟩, fun ⟨_, h, rfl⟩ => h⟩
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
dom_iff_mem
null
get_mem {o : Part α} (h) : get o h ∈ o := ⟨_, rfl⟩ @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
get_mem
null
mem_mk_iff {p : Prop} {o : p → α} {a : α} : a ∈ Part.mk p o ↔ ∃ h, o h = a := Iff.rfl
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_mk_iff
null
@[ext] ext {o p : Part α} (H : ∀ a, a ∈ o ↔ a ∈ p) : o = p := (ext' ⟨fun h => ((H _).1 ⟨h, rfl⟩).fst, fun h => ((H _).2 ⟨h, rfl⟩).fst⟩) fun _ _ => ((H _).2 ⟨_, rfl⟩).snd
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
ext
`Part` extensionality
none : Part α := ⟨False, False.rec⟩
def
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
none
The `none` value in `Part` has a `False` domain and an empty function.
@[simp] notMem_none (a : α) : a ∉ @none α := fun h => h.fst @[deprecated (since := "2025-05-23")] alias not_mem_none := notMem_none
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
notMem_none
null
some (a : α) : Part α := ⟨True, fun _ => a⟩ @[simp]
def
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
some
The `some a` value in `Part` has a `True` domain and the function returns `a`.
some_dom (a : α) : (some a).Dom := trivial
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
some_dom
null
mem_unique : ∀ {a b : α} {o : Part α}, a ∈ o → b ∈ o → a = b | _, _, ⟨_, _⟩, ⟨_, rfl⟩, ⟨_, rfl⟩ => rfl
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_unique
null
mem_right_unique : ∀ {a : α} {o p : Part α}, a ∈ o → a ∈ p → o = p | _, _, _, ⟨ho, _⟩, ⟨hp, _⟩ => ext' (iff_of_true ho hp) (by simp [*])
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_right_unique
null
Mem.left_unique : Relator.LeftUnique ((· ∈ ·) : α → Part α → Prop) := fun _ _ _ => mem_unique
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
Mem.left_unique
null
Mem.right_unique : Relator.RightUnique ((· ∈ ·) : α → Part α → Prop) := fun _ _ _ => mem_right_unique
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
Mem.right_unique
null
get_eq_of_mem {o : Part α} {a} (h : a ∈ o) (h') : get o h' = a := mem_unique ⟨_, rfl⟩ h
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
get_eq_of_mem
null
protected subsingleton (o : Part α) : Set.Subsingleton { a | a ∈ o } := fun _ ha _ hb => mem_unique ha hb @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
subsingleton
null
get_some {a : α} (ha : (some a).Dom) : get (some a) ha = a := rfl
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
get_some
null
mem_some (a : α) : a ∈ some a := ⟨trivial, rfl⟩ @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_some
null
mem_some_iff {a b} : b ∈ (some a : Part α) ↔ b = a := ⟨fun ⟨_, e⟩ => e.symm, fun e => ⟨trivial, e.symm⟩⟩
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_some_iff
null
eq_some_iff {a : α} {o : Part α} : o = some a ↔ a ∈ o := ⟨fun e => e.symm ▸ mem_some _, fun ⟨h, e⟩ => e ▸ ext' (iff_true_intro h) fun _ _ => rfl⟩
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
eq_some_iff
null
eq_none_iff {o : Part α} : o = none ↔ ∀ a, a ∉ o := ⟨fun e => e.symm ▸ notMem_none, fun h => ext (by simpa)⟩
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
eq_none_iff
null
eq_none_iff' {o : Part α} : o = none ↔ ¬o.Dom := ⟨fun e => e.symm ▸ id, fun h => eq_none_iff.2 fun _ h' => h h'.fst⟩ @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
eq_none_iff'
null
not_none_dom : ¬(none : Part α).Dom := id @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
not_none_dom
null
some_ne_none (x : α) : some x ≠ none := by intro h exact true_ne_false (congr_arg Dom h) @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
some_ne_none
null
none_ne_some (x : α) : none ≠ some x := (some_ne_none x).symm
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
none_ne_some
null
ne_none_iff {o : Part α} : o ≠ none ↔ ∃ x, o = some x := by constructor · rw [Ne, eq_none_iff', not_not] exact fun h => ⟨o.get h, eq_some_iff.2 (get_mem h)⟩ · rintro ⟨x, rfl⟩ apply some_ne_none
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
ne_none_iff
null
eq_none_or_eq_some (o : Part α) : o = none ∨ ∃ x, o = some x := or_iff_not_imp_left.2 ne_none_iff.1
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
eq_none_or_eq_some
null
some_injective : Injective (@Part.some α) := fun _ _ h => congr_fun (eq_of_heq (Part.mk.inj h).2) trivial @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
some_injective
null
some_inj {a b : α} : Part.some a = some b ↔ a = b := some_injective.eq_iff @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
some_inj
null
some_get {a : Part α} (ha : a.Dom) : Part.some (Part.get a ha) = a := Eq.symm (eq_some_iff.2 ⟨ha, rfl⟩)
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
some_get
null
get_eq_iff_eq_some {a : Part α} {ha : a.Dom} {b : α} : a.get ha = b ↔ a = some b := ⟨fun h => by simp [h.symm], fun h => by simp [h]⟩
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
get_eq_iff_eq_some
null
get_eq_get_of_eq (a : Part α) (ha : a.Dom) {b : Part α} (h : a = b) : a.get ha = b.get (h ▸ ha) := by congr
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
get_eq_get_of_eq
null
get_eq_iff_mem {o : Part α} {a : α} (h : o.Dom) : o.get h = a ↔ a ∈ o := ⟨fun H => ⟨h, H⟩, fun ⟨_, H⟩ => H⟩
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
get_eq_iff_mem
null
eq_get_iff_mem {o : Part α} {a : α} (h : o.Dom) : a = o.get h ↔ a ∈ o := eq_comm.trans (get_eq_iff_mem h)
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
eq_get_iff_mem
null
eq_of_get_eq_get {a b : Part α} (ha : a.Dom) (hb : b.Dom) (hab : a.get ha = b.get hb) : a = b := ext' (iff_of_true ha hb) fun _ _ => hab
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
eq_of_get_eq_get
null
eq_iff_of_dom {a b : Part α} (ha : a.Dom) (hb : b.Dom) : a.get ha = b.get hb ↔ a = b := ⟨eq_of_get_eq_get ha hb, get_eq_get_of_eq a ha⟩
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
eq_iff_of_dom
null
eq_of_mem {a b : Part α} (ha : a.Dom) (hb : a.get ha ∈ b) : a = b := by have hb' : b.Dom := Part.dom_iff_mem.mpr ⟨a.get ha, hb⟩ rwa [← eq_get_iff_mem hb', eq_iff_of_dom ha hb'] at hb @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
eq_of_mem
null
none_toOption [Decidable (@none α).Dom] : (none : Part α).toOption = Option.none := dif_neg id @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
none_toOption
null
some_toOption (a : α) [Decidable (some a).Dom] : (some a).toOption = Option.some a := dif_pos trivial
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
some_toOption
null
noneDecidable : Decidable (@none α).Dom := instDecidableFalse
instance
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
noneDecidable
null
someDecidable (a : α) : Decidable (some a).Dom := instDecidableTrue
instance
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
someDecidable
null
getOrElse (a : Part α) [Decidable a.Dom] (d : α) := if ha : a.Dom then a.get ha else d
def
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
getOrElse
Retrieves the value of `a : Part α` if it exists, and return the provided default value otherwise.
getOrElse_of_dom (a : Part α) (h : a.Dom) [Decidable a.Dom] (d : α) : getOrElse a d = a.get h := dif_pos h
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
getOrElse_of_dom
null
getOrElse_of_not_dom (a : Part α) (h : ¬a.Dom) [Decidable a.Dom] (d : α) : getOrElse a d = d := dif_neg h @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
getOrElse_of_not_dom
null
getOrElse_none (d : α) [Decidable (none : Part α).Dom] : getOrElse none d = d := none.getOrElse_of_not_dom not_none_dom d @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
getOrElse_none
null
getOrElse_some (a : α) (d : α) [Decidable (some a).Dom] : getOrElse (some a) d = a := (some a).getOrElse_of_dom (some_dom a) d
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
getOrElse_some
null
mem_toOption {o : Part α} [Decidable o.Dom] {a : α} : a ∈ toOption o ↔ a ∈ o := by unfold toOption by_cases h : o.Dom · simpa [h] using ⟨fun h => ⟨_, h⟩, fun ⟨_, h⟩ => h⟩ · simp only [h, ↓reduceDIte, Option.mem_def, reduceCtorEq, false_iff] exact mt Exists.fst h @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_toOption
null
toOption_eq_some_iff {o : Part α} [Decidable o.Dom] {a : α} : toOption o = Option.some a ↔ a ∈ o := by rw [← Option.mem_def, mem_toOption]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
toOption_eq_some_iff
null
protected Dom.toOption {o : Part α} [Decidable o.Dom] (h : o.Dom) : o.toOption = o.get h := dif_pos h
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
Dom.toOption
null
toOption_eq_none_iff {a : Part α} [Decidable a.Dom] : a.toOption = Option.none ↔ ¬a.Dom := Ne.dite_eq_right_iff fun _ => Option.some_ne_none _ @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
toOption_eq_none_iff
null
elim_toOption {α β : Type*} (a : Part α) [Decidable a.Dom] (b : β) (f : α → β) : a.toOption.elim b f = if h : a.Dom then f (a.get h) else b := by split_ifs with h · rw [h.toOption] rfl · rw [Part.toOption_eq_none_iff.2 h] rfl
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
elim_toOption
null
@[coe] ofOption : Option α → Part α | Option.none => none | Option.some a => some a @[simp]
def
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
ofOption
Converts an `Option α` into a `Part α`.
mem_ofOption {a : α} : ∀ {o : Option α}, a ∈ ofOption o ↔ a ∈ o | Option.none => ⟨fun h => h.fst.elim, fun h => Option.noConfusion h⟩ | Option.some _ => ⟨fun h => congr_arg Option.some h.snd, fun h => ⟨trivial, Option.some.inj h⟩⟩ @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_ofOption
null
ofOption_dom {α} : ∀ o : Option α, (ofOption o).Dom ↔ o.isSome | Option.none => by simp [ofOption, none] | Option.some a => by simp [ofOption]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
ofOption_dom
null
ofOption_eq_get {α} (o : Option α) : ofOption o = ⟨_, @Option.get _ o⟩ := Part.ext' (ofOption_dom o) fun h₁ h₂ => by cases o · simp at h₂ · rfl
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
ofOption_eq_get
null
mem_coe {a : α} {o : Option α} : a ∈ (o : Part α) ↔ a ∈ o := mem_ofOption @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_coe
null
coe_none : (@Option.none α : Part α) = none := rfl @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
coe_none
null
coe_some (a : α) : (Option.some a : Part α) = some a := rfl @[elab_as_elim]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
coe_some
null
protected induction_on {P : Part α → Prop} (a : Part α) (hnone : P none) (hsome : ∀ a : α, P (some a)) : P a := (Classical.em a.Dom).elim (fun h => Part.some_get h ▸ hsome _) fun h => (eq_none_iff'.2 h).symm ▸ hnone
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
induction_on
null
ofOptionDecidable : ∀ o : Option α, Decidable (ofOption o).Dom | Option.none => Part.noneDecidable | Option.some a => Part.someDecidable a @[simp]
instance
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
ofOptionDecidable
null
to_ofOption (o : Option α) : toOption (ofOption o) = o := by cases o <;> rfl @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
to_ofOption
null
of_toOption (o : Part α) [Decidable o.Dom] : ofOption (toOption o) = o := ext fun _ => mem_ofOption.trans mem_toOption
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
of_toOption
null
noncomputable equivOption : Part α ≃ Option α := haveI := Classical.dec ⟨fun o => toOption o, ofOption, fun o => of_toOption o, fun o => Eq.trans (by dsimp; congr) (to_ofOption o)⟩
def
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
equivOption
`Part α` is (classically) equivalent to `Option α`.
assert (p : Prop) (f : p → Part α) : Part α := ⟨∃ h : p, (f h).Dom, fun ha => (f ha.fst).get ha.snd⟩
def
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
assert
We give `Part α` the order where everything is greater than `none`. -/ instance : PartialOrder (Part α) where le x y := ∀ i, i ∈ x → i ∈ y le_refl _ _ := id le_trans _ _ _ f g _ := g _ ∘ f _ le_antisymm _ _ f g := Part.ext fun _ => ⟨f _, g _⟩ instance : OrderBot (Part α) where bot := none bot_le := by rintro x _ ⟨⟨_⟩, _⟩ theorem le_total_of_le_of_le {x y : Part α} (z : Part α) (hx : x ≤ z) (hy : y ≤ z) : x ≤ y ∨ y ≤ x := by rcases Part.eq_none_or_eq_some x with (h | ⟨b, h₀⟩) · rw [h] left apply OrderBot.bot_le _ right; intro b' h₁ rw [Part.eq_some_iff] at h₀ have hx := hx _ h₀; have hy := hy _ h₁ have hx := Part.mem_unique hx hy; subst hx exact h₀ /-- `assert p f` is a bind-like operation which appends an additional condition `p` to the domain and uses `f` to produce the value.
protected bind (f : Part α) (g : α → Part β) : Part β := assert (Dom f) fun b => g (f.get b)
def
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
bind
The bind operation has value `g (f.get)`, and is defined when all the parts are defined.
@[simps] map (f : α → β) (o : Part α) : Part β := ⟨o.Dom, f ∘ o.get⟩
def
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
map
The map operation for `Part` just maps the value and maintains the same domain.
mem_map (f : α → β) {o : Part α} : ∀ {a}, a ∈ o → f a ∈ map f o | _, ⟨_, rfl⟩ => ⟨_, rfl⟩ @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_map
null
mem_map_iff (f : α → β) {o : Part α} {b} : b ∈ map f o ↔ ∃ a ∈ o, f a = b := ⟨fun hb => match b, hb with | _, ⟨_, rfl⟩ => ⟨_, ⟨_, rfl⟩, rfl⟩, fun ⟨_, h₁, h₂⟩ => h₂ ▸ mem_map f h₁⟩ @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_map_iff
null
map_none (f : α → β) : map f none = none := eq_none_iff.2 fun a => by simp @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
map_none
null
map_some (f : α → β) (a : α) : map f (some a) = some (f a) := eq_some_iff.2 <| mem_map f <| mem_some _
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
map_some
null
mem_assert {p : Prop} {f : p → Part α} : ∀ {a} (h : p), a ∈ f h → a ∈ assert p f | _, x, ⟨h, rfl⟩ => ⟨⟨x, h⟩, rfl⟩ @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_assert
null
mem_assert_iff {p : Prop} {f : p → Part α} {a} : a ∈ assert p f ↔ ∃ h : p, a ∈ f h := ⟨fun ha => match a, ha with | _, ⟨_, rfl⟩ => ⟨_, ⟨_, rfl⟩⟩, fun ⟨_, h⟩ => mem_assert _ h⟩
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_assert_iff
null
assert_pos {p : Prop} {f : p → Part α} (h : p) : assert p f = f h := by dsimp [assert] cases h' : f h simp only [h', mk.injEq, h, exists_prop_of_true, true_and] apply Function.hfunext · simp only [h, h', exists_prop_of_true] · simp
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
assert_pos
null
assert_neg {p : Prop} {f : p → Part α} (h : ¬p) : assert p f = none := by dsimp [assert, none]; congr · simp only [h, not_false_iff, exists_prop_of_false] · apply Function.hfunext · simp only [h, not_false_iff, exists_prop_of_false] simp at *
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
assert_neg
null
mem_bind {f : Part α} {g : α → Part β} : ∀ {a b}, a ∈ f → b ∈ g a → b ∈ f.bind g | _, _, ⟨h, rfl⟩, ⟨h₂, rfl⟩ => ⟨⟨h, h₂⟩, rfl⟩ @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_bind
null
mem_bind_iff {f : Part α} {g : α → Part β} {b} : b ∈ f.bind g ↔ ∃ a ∈ f, b ∈ g a := ⟨fun hb => match b, hb with | _, ⟨⟨_, _⟩, rfl⟩ => ⟨_, ⟨_, rfl⟩, ⟨_, rfl⟩⟩, fun ⟨_, h₁, h₂⟩ => mem_bind h₁ h₂⟩
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
mem_bind_iff
null
protected Dom.bind {o : Part α} (h : o.Dom) (f : α → Part β) : o.bind f = f (o.get h) := by ext b simp only [Part.mem_bind_iff] refine ⟨?_, fun hb => ⟨o.get h, Part.get_mem _, hb⟩⟩ rintro ⟨a, ha, hb⟩ rwa [Part.get_eq_of_mem ha]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
Dom.bind
null
Dom.of_bind {f : α → Part β} {a : Part α} (h : (a.bind f).Dom) : a.Dom := h.1 @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
Dom.of_bind
null
bind_none (f : α → Part β) : none.bind f = none := eq_none_iff.2 fun a => by simp @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
bind_none
null
bind_some (a : α) (f : α → Part β) : (some a).bind f = f a := ext <| by simp
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
bind_some
null
bind_of_mem {o : Part α} {a : α} (h : a ∈ o) (f : α → Part β) : o.bind f = f a := by rw [eq_some_iff.2 h, bind_some]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
bind_of_mem
null
bind_some_eq_map (f : α → β) (x : Part α) : x.bind (fun y => some (f y)) = map f x := ext <| by simp [eq_comm]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
bind_some_eq_map
null
bind_toOption (f : α → Part β) (o : Part α) [Decidable o.Dom] [∀ a, Decidable (f a).Dom] [Decidable (o.bind f).Dom] : (o.bind f).toOption = o.toOption.elim Option.none fun a => (f a).toOption := by by_cases h : o.Dom · simp_rw [h.toOption, h.bind] rfl · rw [Part.toOption_eq_none_iff.2 h] exact Part.toOption_eq_none_iff.2 fun ho => h ho.of_bind
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
bind_toOption
null
bind_assoc {γ} (f : Part α) (g : α → Part β) (k : β → Part γ) : (f.bind g).bind k = f.bind fun x => (g x).bind k := ext fun a => by simp only [mem_bind_iff] exact ⟨fun ⟨_, ⟨_, h₁, h₂⟩, h₃⟩ => ⟨_, h₁, _, h₂, h₃⟩, fun ⟨_, h₁, _, h₂, h₃⟩ => ⟨_, ⟨_, h₁, h₂⟩, h₃⟩⟩ @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
bind_assoc
null
bind_map {γ} (f : α → β) (x) (g : β → Part γ) : (map f x).bind g = x.bind fun y => g (f y) := by rw [← bind_some_eq_map, bind_assoc]; simp @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
bind_map
null
map_bind {γ} (f : α → Part β) (x : Part α) (g : β → γ) : map g (x.bind f) = x.bind fun y => map g (f y) := by rw [← bind_some_eq_map, bind_assoc]; simp [bind_some_eq_map]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
map_bind
null
map_map (g : β → γ) (f : α → β) (o : Part α) : map g (map f o) = map (g ∘ f) o := by simp [map, Function.comp_assoc]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
map_map
null
map_id' {f : α → α} (H : ∀ x : α, f x = x) (o) : map f o = o := by rw [show f = id from funext H]; exact id_map o @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
map_id'
null
bind_some_right (x : Part α) : x.bind some = x := by rw [bind_some_eq_map] simp [map_id'] @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
bind_some_right
null
pure_eq_some (a : α) : pure a = some a := rfl @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
pure_eq_some
null
ret_eq_some (a : α) : (return a : Part α) = some a := rfl @[simp]
theorem
Data
[ "Mathlib.Algebra.Notation.Defs", "Mathlib.Data.Set.Subsingleton", "Mathlib.Logic.Equiv.Defs" ]
Mathlib/Data/Part.lean
ret_eq_some
null