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recSubsingleton {p : Prop} [h : Decidable p] {h₁ : p → Sort u} {h₂ : ¬p → Sort u} [h₃ : ∀ (h : p), Subsingleton (h₁ h)] [h₄ : ∀ (h : ¬p), Subsingleton (h₂ h)] : Subsingleton (h.casesOn h₂ h₁) := match h with | isTrue h => h₃ h | isFalse h => h₄ h
recSubsingleton {p : Prop} [h : Decidable p] {h₁ : p → Sort u} {h₂ : ¬p → Sort u} [h₃ : ∀ (h : p), Subsingleton (h₁ h)] [h₄ : ∀ (h : ¬p), Subsingleton (h₂ h)] : Subsingleton (h.casesOn h₂ h₁)
match h with | isTrue h => h₃ h | isFalse h => h₄ h
theorem
recSubsingleton
Init
src/Init/Core.lean
[]
[ "Decidable", "Subsingleton" ]
null
1,290
1,299
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Equivalence {α : Sort u} (r : α → α → Prop) : Prop where /-- An equivalence relation is reflexive: `r x x` -/ refl : ∀ x, r x x /-- An equivalence relation is symmetric: `r x y` implies `r y x` -/ symm : ∀ {x y}, r x y → r y x /-- An equivalence relation is transitive: `r x y` and `r y z` implies `r x z` -/...
Equivalence {α : Sort u} (r : α → α → Prop) : Prop where /-- An equivalence relation is reflexive: `r x x` -/ refl : ∀ x, r x x /-- An equivalence relation is symmetric: `r x y` implies `r y x` -/ symm : ∀ {x y}, r x y → r y x /-- An equivalence relation is transitive: `r x y` and `r y z` implies `r x z` -/...
structure
Equivalence
Init
src/Init/Core.lean
[]
[]
An equivalence relation `r : α → α → Prop` is a relation that is * reflexive: `r x x`, * symmetric: `r x y` implies `r y x`, and * transitive: `r x y` and `r y z` implies `r x z`. Equality is an equivalence relation, and equivalence relations share many of the properties of equality.
1,311
1,317
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
emptyRelation {α : Sort u} (_ _ : α) : Prop := False
emptyRelation {α : Sort u} (_ _ : α) : Prop
False
def
emptyRelation
Init
src/Init/Core.lean
[]
[ "False" ]
The empty relation is the relation on `α` which is always `False`.
1,320
1,321
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Subrelation {α : Sort u} (q r : α → α → Prop) := ∀ {x y}, q x y → r x y
Subrelation {α : Sort u} (q r : α → α → Prop)
∀ {x y}, q x y → r x y
def
Subrelation
Init
src/Init/Core.lean
[]
[]
`Subrelation q r` means that `q ⊆ r` or `∀ x y, q x y → r x y`. It is the analogue of the subset relation on relations.
1,327
1,328
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
InvImage {α : Sort u} {β : Sort v} (r : β → β → Prop) (f : α → β) : α → α → Prop := fun a₁ a₂ => r (f a₁) (f a₂)
InvImage {α : Sort u} {β : Sort v} (r : β → β → Prop) (f : α → β) : α → α → Prop
fun a₁ a₂ => r (f a₁) (f a₂)
def
InvImage
Init
src/Init/Core.lean
[]
[]
The inverse image of `r : β → β → Prop` by a function `α → β` is the relation `s : α → α → Prop` defined by `s a b = r (f a) (f b)`.
1,334
1,335
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Relation.TransGen {α : Sort u} (r : α → α → Prop) : α → α → Prop /-- If `r a b`, then `TransGen r a b`. This is the base case of the transitive closure. -/ | single {a b : α} : r a b → TransGen r a b /-- If `TransGen r a b` and `r b c`, then `TransGen r a c`. This is the inductive case of the transitive closure...
Relation.TransGen {α : Sort u} (r : α → α → Prop) : α → α → Prop /-- If `r a b`, then `TransGen r a b`. This is the base case of the transitive closure. -/ | single {a b : α} : r a b → TransGen r a b /-- If `TransGen r a b` and `r b c`, then `TransGen r a c`. This is the inductive case of the transitive closure...
inductive
Relation.TransGen
Init
src/Init/Core.lean
[]
[]
The transitive closure `TransGen r` of a relation `r` is the smallest relation which is transitive and contains `r`. `TransGen r a z` if and only if there exists a sequence `a r b r ... r z` of length at least 1 connecting `a` to `z`.
1,342
1,347
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Relation.TransGen.trans {α : Sort u} {r : α → α → Prop} {a b c} : TransGen r a b → TransGen r b c → TransGen r a c := by intro hab hbc induction hbc with | single h => exact TransGen.tail hab h | tail _ h ih => exact TransGen.tail ih h
Relation.TransGen.trans {α : Sort u} {r : α → α → Prop} {a b c} : TransGen r a b → TransGen r b c → TransGen r a c
by intro hab hbc induction hbc with | single h => exact TransGen.tail hab h | tail _ h ih => exact TransGen.tail ih h
theorem
Relation.TransGen.trans
Init
src/Init/Core.lean
[]
[]
The transitive closure is transitive.
1,350
1,355
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
exists_of_subtype {α : Type u} {p : α → Prop} : { x // p x } → Exists (fun x => p x) | ⟨a, h⟩ => ⟨a, h⟩
exists_of_subtype {α : Type u} {p : α → Prop} : { x // p x } → Exists (fun x => p x) | ⟨a, h⟩ => ⟨a, h⟩
theorem
Subtype.exists_of_subtype
Init
src/Init/Core.lean
[]
[ "Exists" ]
null
1,361
1,362
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
ext : ∀ {a1 a2 : {x // p x}}, val a1 = val a2 → a1 = a2 | ⟨_, _⟩, ⟨_, _⟩, rfl => rfl
ext : ∀ {a1 a2 : {x // p x}}, val a1 = val a2 → a1 = a2 | ⟨_, _⟩, ⟨_, _⟩, rfl => rfl
theorem
Subtype.ext
Init
src/Init/Core.lean
[]
[ "rfl" ]
null
1,366
1,367
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
eq : ∀ {a1 a2 : {x // p x}}, val a1 = val a2 → a1 = a2 | ⟨_, _⟩, ⟨_, _⟩, rfl => rfl
eq : ∀ {a1 a2 : {x // p x}}, val a1 = val a2 → a1 = a2 | ⟨_, _⟩, ⟨_, _⟩, rfl => rfl
theorem
Subtype.eq
Init
src/Init/Core.lean
[]
[ "rfl" ]
null
1,369
1,371
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
eta (a : {x // p x}) (h : p (val a)) : mk (val a) h = a := by cases a exact rfl
eta (a : {x // p x}) (h : p (val a)) : mk (val a) h = a
by cases a exact rfl
theorem
Subtype.eta
Init
src/Init/Core.lean
[]
[ "rfl" ]
null
1,373
1,375
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
{α : Type u} {p : α → Prop} [BEq α] : BEq {x : α // p x} := ⟨fun x y => x.1 == y.1⟩
{α : Type u} {p : α → Prop} [BEq α] : BEq {x : α // p x}
⟨fun x y => x.1 == y.1⟩
instance
Init
src/Init/Core.lean
[]
[ "BEq" ]
null
1,377
1,378
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
{α : Type u} {p : α → Prop} [BEq α] [ReflBEq α] : ReflBEq {x : α // p x} where rfl {x} := BEq.refl x.1
{α : Type u} {p : α → Prop} [BEq α] [ReflBEq α] : ReflBEq {x : α // p x} where rfl {x} := BEq.refl x.1
instance
Init
src/Init/Core.lean
[]
[ "BEq", "BEq.refl", "ReflBEq", "rfl" ]
null
1,380
1,381
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
{α : Type u} {p : α → Prop} [BEq α] [LawfulBEq α] : LawfulBEq {x : α // p x} where eq_of_beq h := Subtype.ext (eq_of_beq h)
{α : Type u} {p : α → Prop} [BEq α] [LawfulBEq α] : LawfulBEq {x : α // p x} where eq_of_beq h := Subtype.ext (eq_of_beq h)
instance
Init
src/Init/Core.lean
[]
[ "BEq", "LawfulBEq", "Subtype.ext" ]
null
1,383
1,384
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
{α : Sort u} {p : α → Prop} [DecidableEq α] : DecidableEq {x : α // p x} := fun ⟨a, h₁⟩ ⟨b, h₂⟩ => if h : a = b then isTrue (by subst h; exact rfl) else isFalse (fun h' => Subtype.noConfusion rfl .rfl (heq_of_eq h') (fun h' => absurd (eq_of_heq h') h))
{α : Sort u} {p : α → Prop} [DecidableEq α] : DecidableEq {x : α // p x}
fun ⟨a, h₁⟩ ⟨b, h₂⟩ => if h : a = b then isTrue (by subst h; exact rfl) else isFalse (fun h' => Subtype.noConfusion rfl .rfl (heq_of_eq h') (fun h' => absurd (eq_of_heq h') h))
instance
Init
src/Init/Core.lean
[]
[ "DecidableEq", "absurd", "eq_of_heq", "heq_of_eq", "rfl" ]
null
1,386
1,389
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Sum.inhabitedLeft [Inhabited α] : Inhabited (Sum α β) where default := Sum.inl default
Sum.inhabitedLeft [Inhabited α] : Inhabited (Sum α β) where default := Sum.inl default
def
Sum.inhabitedLeft
Init
src/Init/Core.lean
[]
[ "Inhabited", "Sum" ]
null
1,398
1,400
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Sum.inhabitedRight [Inhabited β] : Inhabited (Sum α β) where default := Sum.inr default
Sum.inhabitedRight [Inhabited β] : Inhabited (Sum α β) where default := Sum.inr default
def
Sum.inhabitedRight
Init
src/Init/Core.lean
[]
[ "Inhabited", "Sum" ]
null
1,402
1,404
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Sum.nonemptyLeft [h : Nonempty α] : Nonempty (Sum α β) := Nonempty.elim h (fun a => ⟨Sum.inl a⟩)
Sum.nonemptyLeft [h : Nonempty α] : Nonempty (Sum α β)
Nonempty.elim h (fun a => ⟨Sum.inl a⟩)
instance
Sum.nonemptyLeft
Init
src/Init/Core.lean
[]
[ "Nonempty", "Nonempty.elim", "Sum" ]
null
1,406
1,407
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Sum.nonemptyRight [h : Nonempty β] : Nonempty (Sum α β) := Nonempty.elim h (fun b => ⟨Sum.inr b⟩) deriving instance DecidableEq for Sum
Sum.nonemptyRight [h : Nonempty β] : Nonempty (Sum α β)
Nonempty.elim h (fun b => ⟨Sum.inr b⟩) deriving instance DecidableEq for Sum
instance
Sum.nonemptyRight
Init
src/Init/Core.lean
[]
[ "DecidableEq", "Nonempty", "Nonempty.elim", "Sum" ]
null
1,409
1,412
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
[h1 : Nonempty α] [h2 : Nonempty β] : Nonempty (α × β) := Nonempty.elim h1 fun x => Nonempty.elim h2 fun y => ⟨(x, y)⟩
[h1 : Nonempty α] [h2 : Nonempty β] : Nonempty (α × β)
Nonempty.elim h1 fun x => Nonempty.elim h2 fun y => ⟨(x, y)⟩
instance
Init
src/Init/Core.lean
[]
[ "Nonempty", "Nonempty.elim" ]
null
1,418
1,421
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
[h1 : Nonempty α] [h2 : Nonempty β] : Nonempty (MProd α β) := Nonempty.elim h1 fun x => Nonempty.elim h2 fun y => ⟨⟨x, y⟩⟩
[h1 : Nonempty α] [h2 : Nonempty β] : Nonempty (MProd α β)
Nonempty.elim h1 fun x => Nonempty.elim h2 fun y => ⟨⟨x, y⟩⟩
instance
Init
src/Init/Core.lean
[]
[ "MProd", "Nonempty", "Nonempty.elim" ]
null
1,423
1,426
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
[h1 : Nonempty α] [h2 : Nonempty β] : Nonempty (PProd α β) := Nonempty.elim h1 fun x => Nonempty.elim h2 fun y => ⟨⟨x, y⟩⟩
[h1 : Nonempty α] [h2 : Nonempty β] : Nonempty (PProd α β)
Nonempty.elim h1 fun x => Nonempty.elim h2 fun y => ⟨⟨x, y⟩⟩
instance
Init
src/Init/Core.lean
[]
[ "Nonempty", "Nonempty.elim", "PProd" ]
null
1,428
1,431
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
[Inhabited α] [Inhabited β] : Inhabited (α × β) where default := (default, default)
[Inhabited α] [Inhabited β] : Inhabited (α × β) where default := (default, default)
instance
Init
src/Init/Core.lean
[]
[ "Inhabited" ]
null
1,433
1,434
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
[Inhabited α] [Inhabited β] : Inhabited (MProd α β) where default := ⟨default, default⟩
[Inhabited α] [Inhabited β] : Inhabited (MProd α β) where default := ⟨default, default⟩
instance
Init
src/Init/Core.lean
[]
[ "Inhabited", "MProd" ]
null
1,436
1,437
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
[Inhabited α] [Inhabited β] : Inhabited (PProd α β) where default := ⟨default, default⟩
[Inhabited α] [Inhabited β] : Inhabited (PProd α β) where default := ⟨default, default⟩
instance
Init
src/Init/Core.lean
[]
[ "Inhabited", "PProd" ]
null
1,439
1,440
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
[DecidableEq α] [DecidableEq β] : DecidableEq (α × β) := fun (a, b) (a', b') => match decEq a a' with | isTrue e₁ => match decEq b b' with | isTrue e₂ => isTrue (e₁ ▸ e₂ ▸ rfl) | isFalse n₂ => isFalse fun h => Prod.noConfusion rfl rfl (heq_of_eq h) fun _ e₂' => absurd (eq_of_heq e₂') n₂ ...
[DecidableEq α] [DecidableEq β] : DecidableEq (α × β)
fun (a, b) (a', b') => match decEq a a' with | isTrue e₁ => match decEq b b' with | isTrue e₂ => isTrue (e₁ ▸ e₂ ▸ rfl) | isFalse n₂ => isFalse fun h => Prod.noConfusion rfl rfl (heq_of_eq h) fun _ e₂' => absurd (eq_of_heq e₂') n₂ | isFalse n₁ => isFalse fun h => Prod.noConfusion rfl rf...
instance
Init
src/Init/Core.lean
[]
[ "DecidableEq", "absurd", "decEq", "eq_of_heq", "heq_of_eq", "rfl" ]
null
1,442
1,449
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
[BEq α] [BEq β] : BEq (α × β) where beq := fun (a₁, b₁) (a₂, b₂) => a₁ == a₂ && b₁ == b₂
[BEq α] [BEq β] : BEq (α × β) where beq := fun (a₁, b₁) (a₂, b₂) => a₁ == a₂ && b₁ == b₂
instance
Init
src/Init/Core.lean
[]
[ "BEq" ]
null
1,451
1,452
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Prod.lexLt [LT α] [LT β] (s : α × β) (t : α × β) : Prop := s.1 < t.1 ∨ (s.1 = t.1 ∧ s.2 < t.2)
Prod.lexLt [LT α] [LT β] (s : α × β) (t : α × β) : Prop
s.1 < t.1 ∨ (s.1 = t.1 ∧ s.2 < t.2)
def
Prod.lexLt
Init
src/Init/Core.lean
[]
[ "LT" ]
Lexicographical order for products. Two pairs are lexicographically ordered if their first elements are ordered or if their first elements are equal and their second elements are ordered.
1,460
1,461
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Prod.lexLtDec [LT α] [LT β] [DecidableEq α] [(a b : α) → Decidable (a < b)] [(a b : β) → Decidable (a < b)] : (s t : α × β) → Decidable (Prod.lexLt s t) := fun _ _ => inferInstanceAs (Decidable (_ ∨ _))
Prod.lexLtDec [LT α] [LT β] [DecidableEq α] [(a b : α) → Decidable (a < b)] [(a b : β) → Decidable (a < b)] : (s t : α × β) → Decidable (Prod.lexLt s t)
fun _ _ => inferInstanceAs (Decidable (_ ∨ _))
instance
Prod.lexLtDec
Init
src/Init/Core.lean
[]
[ "Decidable", "DecidableEq", "LT", "Prod.lexLt" ]
null
1,463
1,467
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Prod.lexLt_def [LT α] [LT β] (s t : α × β) : (Prod.lexLt s t) = (s.1 < t.1 ∨ (s.1 = t.1 ∧ s.2 < t.2)) := rfl
Prod.lexLt_def [LT α] [LT β] (s t : α × β) : (Prod.lexLt s t) = (s.1 < t.1 ∨ (s.1 = t.1 ∧ s.2 < t.2))
rfl
theorem
Prod.lexLt_def
Init
src/Init/Core.lean
[]
[ "LT", "Prod.lexLt", "rfl" ]
null
1,469
1,470
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Prod.eta (p : α × β) : (p.1, p.2) = p := rfl
Prod.eta (p : α × β) : (p.1, p.2) = p
rfl
theorem
Prod.eta
Init
src/Init/Core.lean
[]
[ "rfl" ]
null
1,472
1,472
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Prod.map {α₁ : Type u₁} {α₂ : Type u₂} {β₁ : Type v₁} {β₂ : Type v₂} (f : α₁ → α₂) (g : β₁ → β₂) : α₁ × β₁ → α₂ × β₂ | (a, b) => (f a, g b)
Prod.map {α₁ : Type u₁} {α₂ : Type u₂} {β₁ : Type v₁} {β₂ : Type v₂} (f : α₁ → α₂) (g : β₁ → β₂) : α₁ × β₁ → α₂ × β₂ | (a, b) => (f a, g b)
def
Prod.map
Init
src/Init/Core.lean
[]
[]
Transforms a pair by applying functions to both elements. Examples: * `(1, 2).map (· + 1) (· * 3) = (2, 6)` * `(1, 2).map toString (· * 3) = ("1", 6)`
1,481
1,483
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Prod.map_apply (f : α → β) (g : γ → δ) (x) (y) : Prod.map f g (x, y) = (f x, g y) := rfl
Prod.map_apply (f : α → β) (g : γ → δ) (x) (y) : Prod.map f g (x, y) = (f x, g y)
rfl
theorem
Prod.map_apply
Init
src/Init/Core.lean
[]
[ "Prod.map", "rfl" ]
null
1,485
1,486
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Prod.map_fst (f : α → β) (g : γ → δ) (x) : (Prod.map f g x).1 = f x.1 := rfl
Prod.map_fst (f : α → β) (g : γ → δ) (x) : (Prod.map f g x).1 = f x.1
rfl
theorem
Prod.map_fst
Init
src/Init/Core.lean
[]
[ "Prod.map", "rfl" ]
null
1,489
1,489
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Prod.map_snd (f : α → β) (g : γ → δ) (x) : (Prod.map f g x).2 = g x.2 := rfl
Prod.map_snd (f : α → β) (g : γ → δ) (x) : (Prod.map f g x).2 = g x.2
rfl
theorem
Prod.map_snd
Init
src/Init/Core.lean
[]
[ "Prod.map", "rfl" ]
null
1,490
1,490
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
{α : Type u} {β : α → Type v} [h₁ : DecidableEq α] [h₂ : ∀ a, DecidableEq (β a)] : DecidableEq (Sigma β) | ⟨a₁, b₁⟩, ⟨a₂, b₂⟩ => match a₁, b₁, a₂, b₂, h₁ a₁ a₂ with | _, b₁, _, b₂, isTrue (Eq.refl _) => match b₁, b₂, h₂ _ b₁ b₂ with | _, _, isTrue (Eq.refl _) => isTrue rfl | _, _, isFals...
{α : Type u} {β : α → Type v} [h₁ : DecidableEq α] [h₂ : ∀ a, DecidableEq (β a)] : DecidableEq (Sigma β) | ⟨a₁, b₁⟩, ⟨a₂, b₂⟩ => match a₁, b₁, a₂, b₂, h₁ a₁ a₂ with | _, b₁, _, b₂, isTrue (Eq.refl _) => match b₁, b₂, h₂ _ b₁ b₂ with | _, _, isTrue (Eq.refl _) => isTrue rfl | _, _, isFals...
instance
Init
src/Init/Core.lean
[]
[ "DecidableEq", "Sigma", "eq_of_heq", "heq_of_eq", "rfl" ]
null
1,494
1,504
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
{α : Sort u} {β : α → Sort v} [h₁ : DecidableEq α] [h₂ : ∀ a, DecidableEq (β a)] : DecidableEq (PSigma β) | ⟨a₁, b₁⟩, ⟨a₂, b₂⟩ => match a₁, b₁, a₂, b₂, h₁ a₁ a₂ with | _, b₁, _, b₂, isTrue (Eq.refl _) => match b₁, b₂, h₂ _ b₁ b₂ with | _, _, isTrue (Eq.refl _) => isTrue rfl | _, _, isFalse n...
{α : Sort u} {β : α → Sort v} [h₁ : DecidableEq α] [h₂ : ∀ a, DecidableEq (β a)] : DecidableEq (PSigma β) | ⟨a₁, b₁⟩, ⟨a₂, b₂⟩ => match a₁, b₁, a₂, b₂, h₁ a₁ a₂ with | _, b₁, _, b₂, isTrue (Eq.refl _) => match b₁, b₂, h₂ _ b₁ b₂ with | _, _, isTrue (Eq.refl _) => isTrue rfl | _, _, isFalse n...
instance
Init
src/Init/Core.lean
[]
[ "DecidableEq", "PSigma", "eq_of_heq", "heq_of_eq", "rfl" ]
null
1,506
1,515
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Exists.of_psigma_prop {α : Sort u} {p : α → Prop} : (PSigma (fun x => p x)) → Exists (fun x => p x) | ⟨x, hx⟩ => ⟨x, hx⟩
Exists.of_psigma_prop {α : Sort u} {p : α → Prop} : (PSigma (fun x => p x)) → Exists (fun x => p x) | ⟨x, hx⟩ => ⟨x, hx⟩
theorem
Exists.of_psigma_prop
Init
src/Init/Core.lean
[]
[ "Exists", "PSigma" ]
null
1,517
1,518
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
PSigma.eta {α : Sort u} {β : α → Sort v} {a₁ a₂ : α} {b₁ : β a₁} {b₂ : β a₂} (h₁ : a₁ = a₂) (h₂ : Eq.ndrec b₁ h₁ = b₂) : PSigma.mk a₁ b₁ = PSigma.mk a₂ b₂ := by subst h₁ subst h₂ exact rfl
PSigma.eta {α : Sort u} {β : α → Sort v} {a₁ a₂ : α} {b₁ : β a₁} {b₂ : β a₂} (h₁ : a₁ = a₂) (h₂ : Eq.ndrec b₁ h₁ = b₂) : PSigma.mk a₁ b₁ = PSigma.mk a₂ b₂
by subst h₁ subst h₂ exact rfl
theorem
PSigma.eta
Init
src/Init/Core.lean
[]
[ "rfl" ]
null
1,520
1,524
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
PUnit.ext (a b : PUnit) : a = b := by cases a; cases b; exact rfl
PUnit.ext (a b : PUnit) : a = b
by cases a; cases b; exact rfl
theorem
PUnit.ext
Init
src/Init/Core.lean
[]
[ "PUnit", "rfl" ]
null
1,528
1,529
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
PUnit.subsingleton (a b : PUnit) : a = b := by cases a; cases b; exact rfl
PUnit.subsingleton (a b : PUnit) : a = b
by cases a; cases b; exact rfl
theorem
PUnit.subsingleton
Init
src/Init/Core.lean
[]
[ "PUnit", "rfl" ]
null
1,531
1,533
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
PUnit.eq_punit (a : PUnit) : a = ⟨⟩ := PUnit.ext a ⟨⟩
PUnit.eq_punit (a : PUnit) : a = ⟨⟩
PUnit.ext a ⟨⟩
theorem
PUnit.eq_punit
Init
src/Init/Core.lean
[]
[ "PUnit", "PUnit.ext" ]
null
1,535
1,536
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
: Subsingleton PUnit := Subsingleton.intro PUnit.ext
: Subsingleton PUnit
Subsingleton.intro PUnit.ext
instance
Init
src/Init/Core.lean
[]
[ "PUnit", "PUnit.ext", "Subsingleton" ]
null
1,538
1,539
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
: Inhabited PUnit where default := ⟨⟩
: Inhabited PUnit where default := ⟨⟩
instance
Init
src/Init/Core.lean
[]
[ "Inhabited", "PUnit" ]
null
1,541
1,542
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
: DecidableEq PUnit := fun a b => isTrue (PUnit.ext a b)
: DecidableEq PUnit
fun a b => isTrue (PUnit.ext a b)
instance
Init
src/Init/Core.lean
[]
[ "DecidableEq", "PUnit", "PUnit.ext" ]
null
1,544
1,545
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Setoid (α : Sort u) where /-- `x ≈ y` is the distinguished equivalence relation of a setoid. -/ r : α → α → Prop /-- The relation `x ≈ y` is an equivalence relation. -/ iseqv : Equivalence r
Setoid (α : Sort u) where /-- `x ≈ y` is the distinguished equivalence relation of a setoid. -/ r : α → α → Prop /-- The relation `x ≈ y` is an equivalence relation. -/ iseqv : Equivalence r
class
Setoid
Init
src/Init/Core.lean
[]
[ "Equivalence" ]
A setoid is a type with a distinguished equivalence relation, denoted `≈`. The `Quotient` type constructor requires a `Setoid` instance.
1,554
1,558
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
{α : Sort u} [Setoid α] : HasEquiv α := ⟨Setoid.r⟩
{α : Sort u} [Setoid α] : HasEquiv α
⟨Setoid.r⟩
instance
Init
src/Init/Core.lean
[]
[ "HasEquiv", "Setoid" ]
null
1,560
1,561
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
refl (a : α) : a ≈ a := iseqv.refl a
refl (a : α) : a ≈ a
iseqv.refl a
theorem
Setoid.refl
Init
src/Init/Core.lean
[]
[]
A setoid's equivalence relation is reflexive.
1,568
1,569
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
symm {a b : α} (hab : a ≈ b) : b ≈ a := iseqv.symm hab
symm {a b : α} (hab : a ≈ b) : b ≈ a
iseqv.symm hab
theorem
Setoid.symm
Init
src/Init/Core.lean
[]
[]
A setoid's equivalence relation is symmetric.
1,572
1,573
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
trans {a b c : α} (hab : a ≈ b) (hbc : b ≈ c) : a ≈ c := iseqv.trans hab hbc
trans {a b c : α} (hab : a ≈ b) (hbc : b ≈ c) : a ≈ c
iseqv.trans hab hbc
theorem
Setoid.trans
Init
src/Init/Core.lean
[]
[]
A setoid's equivalence relation is transitive.
1,576
1,577
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
propext {a b : Prop} : (a ↔ b) → a = b
propext {a b : Prop} : (a ↔ b) → a = b
axiom
propext
Init
src/Init/Core.lean
[]
[]
The [axiom](lean-manual://section/axioms) of **propositional extensionality**. It asserts that if propositions `a` and `b` are logically equivalent (that is, if `a` can be proved from `b` and vice versa), then `a` and `b` are *equal*, meaning `a` can be replaced with `b` in all contexts. The standard logical connectiv...
1,593
1,593
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Eq.propIntro {a b : Prop} (h₁ : a → b) (h₂ : b → a) : a = b := propext <| Iff.intro h₁ h₂
Eq.propIntro {a b : Prop} (h₁ : a → b) (h₂ : b → a) : a = b
propext <| Iff.intro h₁ h₂
theorem
Eq.propIntro
Init
src/Init/Core.lean
[]
[ "propext" ]
null
1,595
1,596
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
{p q : Prop} [d : Decidable (p ↔ q)] : Decidable (p = q) := match d with | isTrue h => isTrue (propext h) | isFalse h => isFalse fun heq => h (heq ▸ Iff.rfl)
{p q : Prop} [d : Decidable (p ↔ q)] : Decidable (p = q)
match d with | isTrue h => isTrue (propext h) | isFalse h => isFalse fun heq => h (heq ▸ Iff.rfl)
instance
Init
src/Init/Core.lean
[]
[ "Decidable", "Iff.rfl", "propext" ]
null
1,599
1,602
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Lean.injEq_helper {P Q R : Prop} : (P → Q → R) → (P ∧ Q → R) := by intro h ⟨h₁,h₂⟩; exact h h₁ h₂ gen_injective_theorems% Array gen_injective_theorems% BitVec gen_injective_theorems% ByteArray gen_injective_theorems% Char gen_injective_theorems% DoResultBC gen_injective_theorems% DoResultPR gen_injective_theorems% D...
Lean.injEq_helper {P Q R : Prop} : (P → Q → R) → (P ∧ Q → R)
by intro h ⟨h₁,h₂⟩; exact h h₁ h₂ gen_injective_theorems% Array gen_injective_theorems% BitVec gen_injective_theorems% ByteArray gen_injective_theorems% Char gen_injective_theorems% DoResultBC gen_injective_theorems% DoResultPR gen_injective_theorems% DoResultPRBC gen_injective_theorems% DoResultSBC gen_injective_theo...
theorem
Lean.injEq_helper
Init
src/Init/Core.lean
[]
[ "Array", "BitVec", "ByteArray", "Char", "DoResultBC", "DoResultPR", "DoResultPRBC", "DoResultSBC", "EStateM.Result", "Except", "Fin", "ForInStep", "Lean.Name", "Lean.Syntax", "List", "MProd", "NonScalar", "Option", "PLift", "PNonScalar", "PProd", "PSigma", "PSum", "Prod...
Helper theorem for proving injectivity theorems
1,605
1,646
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Nat.succ.inj {m n : Nat} : m.succ = n.succ → m = n := fun x => Nat.noConfusion x id
Nat.succ.inj {m n : Nat} : m.succ = n.succ → m = n
fun x => Nat.noConfusion x id
theorem
Nat.succ.inj
Init
src/Init/Core.lean
[]
[ "Nat", "id" ]
null
1,648
1,649
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Nat.succ.injEq (u v : Nat) : (u.succ = v.succ) = (u = v) := Eq.propIntro Nat.succ.inj (congrArg Nat.succ)
Nat.succ.injEq (u v : Nat) : (u.succ = v.succ) = (u = v)
Eq.propIntro Nat.succ.inj (congrArg Nat.succ)
theorem
Nat.succ.injEq
Init
src/Init/Core.lean
[]
[ "Eq.propIntro", "Nat", "Nat.succ.inj", "congrArg" ]
null
1,651
1,652
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
beq_iff_eq [BEq α] [LawfulBEq α] {a b : α} : a == b ↔ a = b := ⟨eq_of_beq, beq_of_eq⟩
beq_iff_eq [BEq α] [LawfulBEq α] {a b : α} : a == b ↔ a = b
⟨eq_of_beq, beq_of_eq⟩
theorem
beq_iff_eq
Init
src/Init/Core.lean
[]
[ "BEq", "LawfulBEq" ]
null
1,654
1,655
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Not.elim {α : Sort _} (H1 : ¬a) (H2 : a) : α := absurd H2 H1
Not.elim {α : Sort _} (H1 : ¬a) (H2 : a) : α
absurd H2 H1
def
Not.elim
Init
src/Init/Core.lean
[]
[ "absurd" ]
*Ex falso* for negation: from `¬a` and `a` anything follows. This is the same as `absurd` with the arguments flipped, but it is in the `Not` namespace so that projection notation can be used.
1,661
1,661
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
And.elim (f : a → b → α) (h : a ∧ b) : α := f h.left h.right
And.elim (f : a → b → α) (h : a ∧ b) : α
f h.left h.right
abbrev
And.elim
Init
src/Init/Core.lean
[]
[]
Non-dependent eliminator for `And`.
1,664
1,664
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Iff.elim (f : (a → b) → (b → a) → α) (h : a ↔ b) : α := f h.mp h.mpr
Iff.elim (f : (a → b) → (b → a) → α) (h : a ↔ b) : α
f h.mp h.mpr
def
Iff.elim
Init
src/Init/Core.lean
[]
[]
Non-dependent eliminator for `Iff`.
1,667
1,667
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Iff.subst {a b : Prop} {p : Prop → Prop} (h₁ : a ↔ b) (h₂ : p a) : p b := Eq.subst (propext h₁) h₂
Iff.subst {a b : Prop} {p : Prop → Prop} (h₁ : a ↔ b) (h₂ : p a) : p b
Eq.subst (propext h₁) h₂
theorem
Iff.subst
Init
src/Init/Core.lean
[]
[ "Eq.subst", "propext" ]
Iff can now be used to do substitutions in a calculation
1,670
1,671
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Not.intro {a : Prop} (h : a → False) : ¬a := h
Not.intro {a : Prop} (h : a → False) : ¬a
h
theorem
Not.intro
Init
src/Init/Core.lean
[]
[ "False" ]
null
1,673
1,673
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Not.imp {a b : Prop} (H2 : ¬b) (H1 : a → b) : ¬a := mt H1 H2
Not.imp {a b : Prop} (H2 : ¬b) (H1 : a → b) : ¬a
mt H1 H2
theorem
Not.imp
Init
src/Init/Core.lean
[]
[ "mt" ]
null
1,675
1,675
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
not_congr (h : a ↔ b) : ¬a ↔ ¬b := ⟨mt h.2, mt h.1⟩
not_congr (h : a ↔ b) : ¬a ↔ ¬b
⟨mt h.2, mt h.1⟩
theorem
not_congr
Init
src/Init/Core.lean
[]
[ "mt" ]
null
1,677
1,677
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
not_not_not : ¬¬¬a ↔ ¬a := ⟨mt not_not_intro, not_not_intro⟩
not_not_not : ¬¬¬a ↔ ¬a
⟨mt not_not_intro, not_not_intro⟩
theorem
not_not_not
Init
src/Init/Core.lean
[]
[ "not_not_intro" ]
null
1,679
1,679
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_of_true (ha : a) (hb : b) : a ↔ b := Iff.intro (fun _ => hb) (fun _ => ha)
iff_of_true (ha : a) (hb : b) : a ↔ b
Iff.intro (fun _ => hb) (fun _ => ha)
theorem
iff_of_true
Init
src/Init/Core.lean
[]
[]
null
1,681
1,681
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_of_false (ha : ¬a) (hb : ¬b) : a ↔ b := Iff.intro ha.elim hb.elim
iff_of_false (ha : ¬a) (hb : ¬b) : a ↔ b
Iff.intro ha.elim hb.elim
theorem
iff_of_false
Init
src/Init/Core.lean
[]
[]
null
1,682
1,682
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_true_left (ha : a) : (a ↔ b) ↔ b := Iff.intro (·.mp ha) (iff_of_true ha)
iff_true_left (ha : a) : (a ↔ b) ↔ b
Iff.intro (·.mp ha) (iff_of_true ha)
theorem
iff_true_left
Init
src/Init/Core.lean
[]
[ "iff_of_true" ]
null
1,684
1,684
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_true_right (ha : a) : (b ↔ a) ↔ b := Iff.comm.trans (iff_true_left ha)
iff_true_right (ha : a) : (b ↔ a) ↔ b
Iff.comm.trans (iff_true_left ha)
theorem
iff_true_right
Init
src/Init/Core.lean
[]
[ "iff_true_left" ]
null
1,685
1,685
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_false_left (ha : ¬a) : (a ↔ b) ↔ ¬b := Iff.intro (mt ·.mpr ha) (iff_of_false ha)
iff_false_left (ha : ¬a) : (a ↔ b) ↔ ¬b
Iff.intro (mt ·.mpr ha) (iff_of_false ha)
theorem
iff_false_left
Init
src/Init/Core.lean
[]
[ "iff_of_false", "mt" ]
null
1,687
1,687
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_false_right (ha : ¬a) : (b ↔ a) ↔ ¬b := Iff.comm.trans (iff_false_left ha)
iff_false_right (ha : ¬a) : (b ↔ a) ↔ ¬b
Iff.comm.trans (iff_false_left ha)
theorem
iff_false_right
Init
src/Init/Core.lean
[]
[ "iff_false_left" ]
null
1,688
1,688
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
of_iff_true (h : a ↔ True) : a := h.mpr trivial
of_iff_true (h : a ↔ True) : a
h.mpr trivial
theorem
of_iff_true
Init
src/Init/Core.lean
[]
[ "True", "trivial" ]
null
1,690
1,690
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_true_intro (h : a) : a ↔ True := iff_of_true h trivial
iff_true_intro (h : a) : a ↔ True
iff_of_true h trivial
theorem
iff_true_intro
Init
src/Init/Core.lean
[]
[ "True", "iff_of_true", "trivial" ]
null
1,691
1,691
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
eq_iff_true_of_subsingleton [Subsingleton α] (x y : α) : x = y ↔ True := iff_true_intro (Subsingleton.elim ..)
eq_iff_true_of_subsingleton [Subsingleton α] (x y : α) : x = y ↔ True
iff_true_intro (Subsingleton.elim ..)
theorem
eq_iff_true_of_subsingleton
Init
src/Init/Core.lean
[]
[ "Subsingleton", "Subsingleton.elim", "True", "iff_true_intro" ]
null
1,693
1,694
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
not_of_iff_false : (p ↔ False) → ¬p := Iff.mp
not_of_iff_false : (p ↔ False) → ¬p
Iff.mp
theorem
not_of_iff_false
Init
src/Init/Core.lean
[]
[ "False" ]
null
1,696
1,696
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_false_intro (h : ¬a) : a ↔ False := iff_of_false h id
iff_false_intro (h : ¬a) : a ↔ False
iff_of_false h id
theorem
iff_false_intro
Init
src/Init/Core.lean
[]
[ "False", "id", "iff_of_false" ]
null
1,697
1,697
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
not_iff_false_intro (h : a) : ¬a ↔ False := iff_false_intro (not_not_intro h)
not_iff_false_intro (h : a) : ¬a ↔ False
iff_false_intro (not_not_intro h)
theorem
not_iff_false_intro
Init
src/Init/Core.lean
[]
[ "False", "iff_false_intro", "not_not_intro" ]
null
1,699
1,699
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
not_true : (¬True) ↔ False := iff_false_intro (not_not_intro trivial)
not_true : (¬True) ↔ False
iff_false_intro (not_not_intro trivial)
theorem
not_true
Init
src/Init/Core.lean
[]
[ "False", "True", "iff_false_intro", "not_not_intro", "trivial" ]
null
1,700
1,700
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
not_false_iff : (¬False) ↔ True := iff_true_intro not_false
not_false_iff : (¬False) ↔ True
iff_true_intro not_false
theorem
not_false_iff
Init
src/Init/Core.lean
[]
[ "False", "True", "iff_true_intro", "not_false" ]
null
1,702
1,702
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Eq.to_iff : a = b → (a ↔ b) := Iff.of_eq
Eq.to_iff : a = b → (a ↔ b)
Iff.of_eq
theorem
Eq.to_iff
Init
src/Init/Core.lean
[]
[ "Iff.of_eq" ]
null
1,704
1,704
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_of_eq : a = b → (a ↔ b) := Iff.of_eq
iff_of_eq : a = b → (a ↔ b)
Iff.of_eq
theorem
iff_of_eq
Init
src/Init/Core.lean
[]
[ "Iff.of_eq" ]
null
1,705
1,705
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
neq_of_not_iff : ¬(a ↔ b) → a ≠ b := mt Iff.of_eq
neq_of_not_iff : ¬(a ↔ b) → a ≠ b
mt Iff.of_eq
theorem
neq_of_not_iff
Init
src/Init/Core.lean
[]
[ "Iff.of_eq", "mt" ]
null
1,706
1,706
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_iff_eq : (a ↔ b) ↔ a = b := Iff.intro propext Iff.of_eq
iff_iff_eq : (a ↔ b) ↔ a = b
Iff.intro propext Iff.of_eq
theorem
iff_iff_eq
Init
src/Init/Core.lean
[]
[ "Iff.of_eq", "propext" ]
null
1,708
1,708
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
eq_iff_iff : (a = b) ↔ (a ↔ b) := iff_iff_eq.symm
eq_iff_iff : (a = b) ↔ (a ↔ b)
iff_iff_eq.symm
theorem
eq_iff_iff
Init
src/Init/Core.lean
[]
[]
null
1,709
1,709
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
eq_self_iff_true (a : α) : a = a ↔ True := iff_true_intro rfl
eq_self_iff_true (a : α) : a = a ↔ True
iff_true_intro rfl
theorem
eq_self_iff_true
Init
src/Init/Core.lean
[]
[ "True", "iff_true_intro", "rfl" ]
null
1,711
1,711
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
ne_self_iff_false (a : α) : a ≠ a ↔ False := not_iff_false_intro rfl
ne_self_iff_false (a : α) : a ≠ a ↔ False
not_iff_false_intro rfl
theorem
ne_self_iff_false
Init
src/Init/Core.lean
[]
[ "False", "not_iff_false_intro", "rfl" ]
null
1,712
1,712
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
false_of_true_iff_false (h : True ↔ False) : False := h.mp trivial
false_of_true_iff_false (h : True ↔ False) : False
h.mp trivial
theorem
false_of_true_iff_false
Init
src/Init/Core.lean
[]
[ "False", "True", "trivial" ]
null
1,714
1,714
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
false_of_true_eq_false (h : True = False) : False := false_of_true_iff_false (Iff.of_eq h)
false_of_true_eq_false (h : True = False) : False
false_of_true_iff_false (Iff.of_eq h)
theorem
false_of_true_eq_false
Init
src/Init/Core.lean
[]
[ "False", "Iff.of_eq", "True", "false_of_true_iff_false" ]
null
1,715
1,715
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
true_eq_false_of_false : False → (True = False) := False.elim
true_eq_false_of_false : False → (True = False)
False.elim
theorem
true_eq_false_of_false
Init
src/Init/Core.lean
[]
[ "False", "False.elim", "True" ]
null
1,717
1,717
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_def : (a ↔ b) ↔ (a → b) ∧ (b → a) := iff_iff_implies_and_implies
iff_def : (a ↔ b) ↔ (a → b) ∧ (b → a)
iff_iff_implies_and_implies
theorem
iff_def
Init
src/Init/Core.lean
[]
[ "iff_iff_implies_and_implies" ]
null
1,719
1,719
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_def' : (a ↔ b) ↔ (b → a) ∧ (a → b) := Iff.trans iff_def And.comm
iff_def' : (a ↔ b) ↔ (b → a) ∧ (a → b)
Iff.trans iff_def And.comm
theorem
iff_def'
Init
src/Init/Core.lean
[]
[ "And.comm", "Iff.trans", "iff_def" ]
null
1,720
1,720
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
true_iff_false : (True ↔ False) ↔ False := iff_false_intro (·.mp True.intro)
true_iff_false : (True ↔ False) ↔ False
iff_false_intro (·.mp True.intro)
theorem
true_iff_false
Init
src/Init/Core.lean
[]
[ "False", "True", "iff_false_intro" ]
null
1,722
1,722
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
false_iff_true : (False ↔ True) ↔ False := iff_false_intro (·.mpr True.intro)
false_iff_true : (False ↔ True) ↔ False
iff_false_intro (·.mpr True.intro)
theorem
false_iff_true
Init
src/Init/Core.lean
[]
[ "False", "True", "iff_false_intro" ]
null
1,723
1,723
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
iff_not_self : ¬(a ↔ ¬a) | H => let f h := H.1 h h; f (H.2 f)
iff_not_self : ¬(a ↔ ¬a) | H => let f h
H.1 h h; f (H.2 f)
theorem
iff_not_self
Init
src/Init/Core.lean
[]
[]
null
1,725
1,725
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
heq_self_iff_true (a : α) : a ≍ a ↔ True := iff_true_intro HEq.rfl
heq_self_iff_true (a : α) : a ≍ a ↔ True
iff_true_intro HEq.rfl
theorem
heq_self_iff_true
Init
src/Init/Core.lean
[]
[ "HEq.rfl", "True", "iff_true_intro" ]
null
1,726
1,726
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
not_not_of_not_imp : ¬(a → b) → ¬¬a := mt Not.elim
not_not_of_not_imp : ¬(a → b) → ¬¬a
mt Not.elim
theorem
not_not_of_not_imp
Init
src/Init/Core.lean
[]
[ "Not.elim", "mt" ]
null
1,730
1,730
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
not_of_not_imp {a : Prop} : ¬(a → b) → ¬b := mt fun h _ => h
not_of_not_imp {a : Prop} : ¬(a → b) → ¬b
mt fun h _ => h
theorem
not_of_not_imp
Init
src/Init/Core.lean
[]
[ "mt" ]
null
1,732
1,732
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_not_self : (a → ¬a) ↔ ¬a := Iff.intro (fun h ha => h ha ha) (fun h _ => h)
imp_not_self : (a → ¬a) ↔ ¬a
Iff.intro (fun h ha => h ha ha) (fun h _ => h)
theorem
imp_not_self
Init
src/Init/Core.lean
[]
[]
null
1,734
1,734
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_intro {α β : Prop} (h : α) : β → α := fun _ => h
imp_intro {α β : Prop} (h : α) : β → α
fun _ => h
theorem
imp_intro
Init
src/Init/Core.lean
[]
[]
null
1,736
1,736
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_imp_imp {a b c d : Prop} (h₀ : c → a) (h₁ : b → d) : (a → b) → (c → d) := (h₁ ∘ · ∘ h₀)
imp_imp_imp {a b c d : Prop} (h₀ : c → a) (h₁ : b → d) : (a → b) → (c → d)
(h₁ ∘ · ∘ h₀)
theorem
imp_imp_imp
Init
src/Init/Core.lean
[]
[]
null
1,738
1,738
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6