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imp_iff_right {a : Prop} (ha : a) : (a → b) ↔ b := Iff.intro (· ha) (fun a _ => a)
imp_iff_right {a : Prop} (ha : a) : (a → b) ↔ b
Iff.intro (· ha) (fun a _ => a)
theorem
imp_iff_right
Init
src/Init/Core.lean
[]
[]
null
1,740
1,740
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_true_iff (α : Sort u) : (α → True) ↔ True := iff_true_intro (fun _ => trivial)
imp_true_iff (α : Sort u) : (α → True) ↔ True
iff_true_intro (fun _ => trivial)
theorem
imp_true_iff
Init
src/Init/Core.lean
[]
[ "True", "iff_true_intro", "trivial" ]
null
1,743
1,743
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
false_imp_iff (a : Prop) : (False → a) ↔ True := iff_true_intro False.elim
false_imp_iff (a : Prop) : (False → a) ↔ True
iff_true_intro False.elim
theorem
false_imp_iff
Init
src/Init/Core.lean
[]
[ "False", "False.elim", "True", "iff_true_intro" ]
null
1,745
1,745
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
true_imp_iff {α : Prop} : (True → α) ↔ α := imp_iff_right True.intro
true_imp_iff {α : Prop} : (True → α) ↔ α
imp_iff_right True.intro
theorem
true_imp_iff
Init
src/Init/Core.lean
[]
[ "True", "imp_iff_right" ]
null
1,747
1,747
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_self : (a → a) ↔ True := iff_true_intro id
imp_self : (a → a) ↔ True
iff_true_intro id
theorem
imp_self
Init
src/Init/Core.lean
[]
[ "True", "id", "iff_true_intro" ]
null
1,749
1,749
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_false : (a → False) ↔ ¬a := Iff.rfl
imp_false : (a → False) ↔ ¬a
Iff.rfl
theorem
imp_false
Init
src/Init/Core.lean
[]
[ "False", "Iff.rfl" ]
null
1,751
1,751
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp.swap : (a → b → c) ↔ (b → a → c) := Iff.intro flip flip
imp.swap : (a → b → c) ↔ (b → a → c)
Iff.intro flip flip
theorem
imp.swap
Init
src/Init/Core.lean
[]
[ "flip" ]
null
1,753
1,753
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_not_comm : (a → ¬b) ↔ (b → ¬a) := imp.swap
imp_not_comm : (a → ¬b) ↔ (b → ¬a)
imp.swap
theorem
imp_not_comm
Init
src/Init/Core.lean
[]
[ "imp.swap" ]
null
1,755
1,755
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_congr_left (h : a ↔ b) : (a → c) ↔ (b → c) := Iff.intro (· ∘ h.mpr) (· ∘ h.mp)
imp_congr_left (h : a ↔ b) : (a → c) ↔ (b → c)
Iff.intro (· ∘ h.mpr) (· ∘ h.mp)
theorem
imp_congr_left
Init
src/Init/Core.lean
[]
[]
null
1,757
1,757
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_congr_right (h : a → (b ↔ c)) : (a → b) ↔ (a → c) := Iff.intro (fun hab ha => (h ha).mp (hab ha)) (fun hcd ha => (h ha).mpr (hcd ha))
imp_congr_right (h : a → (b ↔ c)) : (a → b) ↔ (a → c)
Iff.intro (fun hab ha => (h ha).mp (hab ha)) (fun hcd ha => (h ha).mpr (hcd ha))
theorem
imp_congr_right
Init
src/Init/Core.lean
[]
[]
null
1,759
1,760
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_congr_ctx (h₁ : a ↔ c) (h₂ : c → (b ↔ d)) : (a → b) ↔ (c → d) := Iff.trans (imp_congr_left h₁) (imp_congr_right h₂)
imp_congr_ctx (h₁ : a ↔ c) (h₂ : c → (b ↔ d)) : (a → b) ↔ (c → d)
Iff.trans (imp_congr_left h₁) (imp_congr_right h₂)
theorem
imp_congr_ctx
Init
src/Init/Core.lean
[]
[ "Iff.trans", "imp_congr_left", "imp_congr_right" ]
null
1,762
1,763
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_congr (h₁ : a ↔ c) (h₂ : b ↔ d) : (a → b) ↔ (c → d) := imp_congr_ctx h₁ fun _ => h₂
imp_congr (h₁ : a ↔ c) (h₂ : b ↔ d) : (a → b) ↔ (c → d)
imp_congr_ctx h₁ fun _ => h₂
theorem
imp_congr
Init
src/Init/Core.lean
[]
[ "imp_congr_ctx" ]
null
1,765
1,765
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
imp_iff_not (hb : ¬b) : a → b ↔ ¬a := imp_congr_right fun _ => iff_false_intro hb
imp_iff_not (hb : ¬b) : a → b ↔ ¬a
imp_congr_right fun _ => iff_false_intro hb
theorem
imp_iff_not
Init
src/Init/Core.lean
[]
[ "iff_false_intro", "imp_congr_right" ]
null
1,767
1,767
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
sound : ∀ {α : Sort u} {r : α → α → Prop} {a b : α}, r a b → Quot.mk r a = Quot.mk r b
sound : ∀ {α : Sort u} {r : α → α → Prop} {a b : α}, r a b → Quot.mk r a = Quot.mk r b
axiom
Quot.sound
Init
src/Init/Core.lean
[]
[]
The **quotient axiom**, which asserts the equality of elements related by the quotient's relation. The relation `r` does not need to be an equivalence relation to use this axiom. When `r` is not an equivalence relation, the quotient is with respect to the equivalence relation generated by `r`. `Quot.sound` is part of...
1,789
1,789
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
liftBeta {α : Sort u} {r : α → α → Prop} {β : Sort v} (f : α → β) (c : (a b : α) → r a b → f a = f b) (a : α) : lift f c (Quot.mk r a) = f a := rfl
liftBeta {α : Sort u} {r : α → α → Prop} {β : Sort v} (f : α → β) (c : (a b : α) → r a b → f a = f b) (a : α) : lift f c (Quot.mk r a) = f a
rfl
theorem
Quot.liftBeta
Init
src/Init/Core.lean
[]
[ "rfl" ]
null
1,791
1,796
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
indBeta {α : Sort u} {r : α → α → Prop} {motive : Quot r → Prop} (p : (a : α) → motive (Quot.mk r a)) (a : α) : (ind p (Quot.mk r a) : motive (Quot.mk r a)) = p a := rfl
indBeta {α : Sort u} {r : α → α → Prop} {motive : Quot r → Prop} (p : (a : α) → motive (Quot.mk r a)) (a : α) : (ind p (Quot.mk r a) : motive (Quot.mk r a)) = p a
rfl
theorem
Quot.indBeta
Init
src/Init/Core.lean
[]
[ "rfl" ]
null
1,798
1,802
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
liftOn {α : Sort u} {β : Sort v} {r : α → α → Prop} (q : Quot r) (f : α → β) (c : (a b : α) → r a b → f a = f b) : β := lift f c q
liftOn {α : Sort u} {β : Sort v} {r : α → α → Prop} (q : Quot r) (f : α → β) (c : (a b : α) → r a b → f a = f b) : β
lift f c q
abbrev
Quot.liftOn
Init
src/Init/Core.lean
[]
[]
Lifts a function from an underlying type to a function on a quotient, requiring that it respects the quotient's relation. Given a relation `r : α → α → Prop` and a quotient's value `q : Quot r`, applying a `f : α → β` requires a proof `c` that `f` respects `r`. In this case, `Quot.liftOn q f h : β` evaluates to the re...
1,817
1,819
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
inductionOn {α : Sort u} {r : α → α → Prop} {motive : Quot r → Prop} (q : Quot r) (h : (a : α) → motive (Quot.mk r a)) : motive q := ind h q
inductionOn {α : Sort u} {r : α → α → Prop} {motive : Quot r → Prop} (q : Quot r) (h : (a : α) → motive (Quot.mk r a)) : motive q
ind h q
theorem
Quot.inductionOn
Init
src/Init/Core.lean
[]
[]
null
1,821
1,826
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
exists_rep {α : Sort u} {r : α → α → Prop} (q : Quot r) : Exists (fun a => (Quot.mk r a) = q) := q.inductionOn (fun a => ⟨a, rfl⟩)
exists_rep {α : Sort u} {r : α → α → Prop} (q : Quot r) : Exists (fun a => (Quot.mk r a) = q)
q.inductionOn (fun a => ⟨a, rfl⟩)
theorem
Quot.exists_rep
Init
src/Init/Core.lean
[]
[ "Exists" ]
null
1,828
1,829
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
indep (f : (a : α) → motive (Quot.mk r a)) (a : α) : PSigma motive := ⟨Quot.mk r a, f a⟩
indep (f : (a : α) → motive (Quot.mk r a)) (a : α) : PSigma motive
⟨Quot.mk r a, f a⟩
def
Quot.indep
Init
src/Init/Core.lean
[]
[ "PSigma" ]
Auxiliary definition for `Quot.rec`.
1,837
1,839
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
indepCoherent (f : (a : α) → motive (Quot.mk r a)) (h : (a b : α) → (p : r a b) → Eq.ndrec (f a) (sound p) = f b) : (a b : α) → r a b → Quot.indep f a = Quot.indep f b := fun a b e => PSigma.eta (sound e) (h a b e)
indepCoherent (f : (a : α) → motive (Quot.mk r a)) (h : (a b : α) → (p : r a b) → Eq.ndrec (f a) (sound p) = f b) : (a b : α) → r a b → Quot.indep f a = Quot.indep f b
fun a b e => PSigma.eta (sound e) (h a b e)
theorem
Quot.indepCoherent
Init
src/Init/Core.lean
[]
[ "PSigma.eta", "Quot.indep" ]
null
1,841
1,845
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
liftIndepPr1 (f : (a : α) → motive (Quot.mk r a)) (h : ∀ (a b : α) (p : r a b), Eq.ndrec (f a) (sound p) = f b) (q : Quot r) : (lift (Quot.indep f) (Quot.indepCoherent f h) q).1 = q := by induction q using Quot.ind exact rfl
liftIndepPr1 (f : (a : α) → motive (Quot.mk r a)) (h : ∀ (a b : α) (p : r a b), Eq.ndrec (f a) (sound p) = f b) (q : Quot r) : (lift (Quot.indep f) (Quot.indepCoherent f h) q).1 = q
by induction q using Quot.ind exact rfl
theorem
Quot.liftIndepPr1
Init
src/Init/Core.lean
[]
[ "Quot.indep", "Quot.indepCoherent", "rfl" ]
null
1,847
1,853
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
rec (f : (a : α) → motive (Quot.mk r a)) (h : (a b : α) → (p : r a b) → Eq.ndrec (f a) (sound p) = f b) (q : Quot r) : motive q := Eq.ndrecOn (Quot.liftIndepPr1 f h q) ((lift (Quot.indep f) (Quot.indepCoherent f h) q).2)
rec (f : (a : α) → motive (Quot.mk r a)) (h : (a b : α) → (p : r a b) → Eq.ndrec (f a) (sound p) = f b) (q : Quot r) : motive q
Eq.ndrecOn (Quot.liftIndepPr1 f h q) ((lift (Quot.indep f) (Quot.indepCoherent f h) q).2)
abbrev
Quot.rec
Init
src/Init/Core.lean
[]
[ "Quot.indep", "Quot.indepCoherent", "Quot.liftIndepPr1" ]
A dependent recursion principle for `Quot`. It is analogous to the [recursor](lean-manual://section/recursors) for a structure, and can be used when the resulting type is not necessarily a proposition. While it is very general, this recursor can be tricky to use. The following simpler alternatives may be easier to use...
1,870
1,874
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
recOn (q : Quot r) (f : (a : α) → motive (Quot.mk r a)) (h : (a b : α) → (p : r a b) → Eq.ndrec (f a) (sound p) = f b) : motive q := q.rec f h
recOn (q : Quot r) (f : (a : α) → motive (Quot.mk r a)) (h : (a b : α) → (p : r a b) → Eq.ndrec (f a) (sound p) = f b) : motive q
q.rec f h
abbrev
Quot.recOn
Init
src/Init/Core.lean
[]
[]
A dependent recursion principle for `Quot` that takes the quotient first. It is analogous to the [recursor](lean-manual://section/recursors) for a structure, and can be used when the resulting type is not necessarily a proposition. While it is very general, this recursor can be tricky to use. The following simpler alt...
1,891
1,896
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
recOnSubsingleton [h : (a : α) → Subsingleton (motive (Quot.mk r a))] (q : Quot r) (f : (a : α) → motive (Quot.mk r a)) : motive q := by induction q using Quot.rec apply f apply Subsingleton.elim
recOnSubsingleton [h : (a : α) → Subsingleton (motive (Quot.mk r a))] (q : Quot r) (f : (a : α) → motive (Quot.mk r a)) : motive q
by induction q using Quot.rec apply f apply Subsingleton.elim
abbrev
Quot.recOnSubsingleton
Init
src/Init/Core.lean
[]
[ "Quot.rec", "Subsingleton", "Subsingleton.elim" ]
An alternative induction principle for quotients that can be used when the target type is a subsingleton, in which all elements are equal. In these cases, the proof that the function respects the quotient's relation is trivial, so any function can be lifted. `Quot.rec` does not assume that the type is a subsingleton.
1,907
1,914
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
hrecOn (q : Quot r) (f : (a : α) → motive (Quot.mk r a)) (c : (a b : α) → (p : r a b) → f a ≍ f b) : motive q := Quot.recOn q f fun a b p => eq_of_heq (eqRec_heq_iff.mpr (c a b p))
hrecOn (q : Quot r) (f : (a : α) → motive (Quot.mk r a)) (c : (a b : α) → (p : r a b) → f a ≍ f b) : motive q
Quot.recOn q f fun a b p => eq_of_heq (eqRec_heq_iff.mpr (c a b p))
abbrev
Quot.hrecOn
Init
src/Init/Core.lean
[]
[ "Quot.recOn", "eq_of_heq" ]
A dependent recursion principle for `Quot` that uses [heterogeneous equality](lean-manual://section/HEq), analogous to a [recursor](lean-manual://section/recursors) for a structure. `Quot.recOn` is a version of this recursor that uses `Eq` instead of `HEq`.
1,923
1,928
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Quotient {α : Sort u} (s : Setoid α) := @Quot α Setoid.r
Quotient {α : Sort u} (s : Setoid α)
@Quot α Setoid.r
def
Quotient
Init
src/Init/Core.lean
[]
[ "Setoid" ]
Quotient types coarsen the propositional equality for a type so that terms related by some equivalence relation are considered equal. The equivalence relation is given by an instance of `Setoid`. Set-theoretically, `Quotient s` can seen as the set of equivalence classes of `α` modulo the `Setoid` instance's relation `...
1,955
1,956
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
mk {α : Sort u} (s : Setoid α) (a : α) : Quotient s := Quot.mk Setoid.r a
mk {α : Sort u} (s : Setoid α) (a : α) : Quotient s
Quot.mk Setoid.r a
def
Quotient.mk
Init
src/Init/Core.lean
[]
[ "Quotient", "Setoid" ]
Places an element of a type into the quotient that equates terms according to an equivalence relation. The setoid instance is provided explicitly. `Quotient.mk'` uses instance synthesis instead. Given `v : α`, `Quotient.mk s v : Quotient s` is like `v`, except all observations of `v`'s value must respect `s.r`. `Quot...
1,970
1,972
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
mk' {α : Sort u} [s : Setoid α] (a : α) : Quotient s := Quotient.mk s a
mk' {α : Sort u} [s : Setoid α] (a : α) : Quotient s
Quotient.mk s a
def
Quotient.mk'
Init
src/Init/Core.lean
[]
[ "Quotient", "Quotient.mk", "Setoid" ]
Places an element of a type into the quotient that equates terms according to an equivalence relation. The equivalence relation is found by synthesizing a `Setoid` instance. `Quotient.mk` instead expects the instance to be provided explicitly. Given `v : α`, `Quotient.mk' v : Quotient s` is like `v`, except all obser...
1,986
1,987
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
sound {α : Sort u} {s : Setoid α} {a b : α} : a ≈ b → Quotient.mk s a = Quotient.mk s b := Quot.sound
sound {α : Sort u} {s : Setoid α} {a b : α} : a ≈ b → Quotient.mk s a = Quotient.mk s b
Quot.sound
theorem
Quotient.sound
Init
src/Init/Core.lean
[]
[ "Quot.sound", "Quotient.mk", "Setoid" ]
The **quotient axiom**, which asserts the equality of elements related in the setoid. Because `Quotient` is built on a lower-level type `Quot`, `Quotient.sound` is implemented as a theorem. It is derived from `Quot.sound`, the soundness axiom for the lower-level quotient type `Quot`.
1,996
1,997
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
lift {α : Sort u} {β : Sort v} {s : Setoid α} (f : α → β) : ((a b : α) → a ≈ b → f a = f b) → Quotient s → β := Quot.lift f
lift {α : Sort u} {β : Sort v} {s : Setoid α} (f : α → β) : ((a b : α) → a ≈ b → f a = f b) → Quotient s → β
Quot.lift f
abbrev
Quotient.lift
Init
src/Init/Core.lean
[]
[ "Quotient", "Setoid" ]
Lifts a function from an underlying type to a function on a quotient, requiring that it respects the quotient's equivalence relation. Given `s : Setoid α` and a quotient `Quotient s`, applying a function `f : α → β` requires a proof `h` that `f` respects the equivalence relation `s.r`. In this case, the function `Quot...
2,010
2,011
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
ind {α : Sort u} {s : Setoid α} {motive : Quotient s → Prop} : ((a : α) → motive (Quotient.mk s a)) → (q : Quotient s) → motive q := Quot.ind
ind {α : Sort u} {s : Setoid α} {motive : Quotient s → Prop} : ((a : α) → motive (Quotient.mk s a)) → (q : Quotient s) → motive q
Quot.ind
theorem
Quotient.ind
Init
src/Init/Core.lean
[]
[ "Quotient", "Quotient.mk", "Setoid" ]
A reasoning principle for quotients that allows proofs about quotients to assume that all values are constructed with `Quotient.mk`.
2,017
2,018
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
liftOn {α : Sort u} {β : Sort v} {s : Setoid α} (q : Quotient s) (f : α → β) (c : (a b : α) → a ≈ b → f a = f b) : β := Quot.liftOn q f c
liftOn {α : Sort u} {β : Sort v} {s : Setoid α} (q : Quotient s) (f : α → β) (c : (a b : α) → a ≈ b → f a = f b) : β
Quot.liftOn q f c
abbrev
Quotient.liftOn
Init
src/Init/Core.lean
[]
[ "Quot.liftOn", "Quotient", "Setoid" ]
Lifts a function from an underlying type to a function on a quotient, requiring that it respects the quotient's equivalence relation. Given `s : Setoid α` and a quotient value `q : Quotient s`, applying a function `f : α → β` requires a proof `c` that `f` respects the equivalence relation `s.r`. In this case, the term...
2,031
2,032
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
inductionOn {α : Sort u} {s : Setoid α} {motive : Quotient s → Prop} (q : Quotient s) (h : (a : α) → motive (Quotient.mk s a)) : motive q := Quot.inductionOn q h
inductionOn {α : Sort u} {s : Setoid α} {motive : Quotient s → Prop} (q : Quotient s) (h : (a : α) → motive (Quotient.mk s a)) : motive q
Quot.inductionOn q h
theorem
Quotient.inductionOn
Init
src/Init/Core.lean
[]
[ "Quot.inductionOn", "Quotient", "Quotient.mk", "Setoid" ]
The analogue of `Quot.inductionOn`: every element of `Quotient s` is of the form `Quotient.mk s a`.
2,035
2,040
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
exists_rep {α : Sort u} {s : Setoid α} (q : Quotient s) : Exists (fun (a : α) => Quotient.mk s a = q) := Quot.exists_rep q
exists_rep {α : Sort u} {s : Setoid α} (q : Quotient s) : Exists (fun (a : α) => Quotient.mk s a = q)
Quot.exists_rep q
theorem
Quotient.exists_rep
Init
src/Init/Core.lean
[]
[ "Exists", "Quot.exists_rep", "Quotient", "Quotient.mk", "Setoid" ]
null
2,042
2,043
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
rec (f : (a : α) → motive (Quotient.mk s a)) (h : (a b : α) → (p : a ≈ b) → Eq.ndrec (f a) (Quotient.sound p) = f b) (q : Quotient s) : motive q := Quot.rec f h q
rec (f : (a : α) → motive (Quotient.mk s a)) (h : (a b : α) → (p : a ≈ b) → Eq.ndrec (f a) (Quotient.sound p) = f b) (q : Quotient s) : motive q
Quot.rec f h q
def
Quotient.rec
Init
src/Init/Core.lean
[]
[ "Quot.rec", "Quotient", "Quotient.mk", "Quotient.sound" ]
A dependent recursion principle for `Quotient`. It is analogous to the [recursor](lean-manual://section/recursors) for a structure, and can be used when the resulting type is not necessarily a proposition. While it is very general, this recursor can be tricky to use. The following simpler alternatives may be easier to...
2,065
2,071
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
recOn (q : Quotient s) (f : (a : α) → motive (Quotient.mk s a)) (h : (a b : α) → (p : a ≈ b) → Eq.ndrec (f a) (Quotient.sound p) = f b) : motive q := Quot.recOn q f h
recOn (q : Quotient s) (f : (a : α) → motive (Quotient.mk s a)) (h : (a b : α) → (p : a ≈ b) → Eq.ndrec (f a) (Quotient.sound p) = f b) : motive q
Quot.recOn q f h
abbrev
Quotient.recOn
Init
src/Init/Core.lean
[]
[ "Quot.recOn", "Quotient", "Quotient.mk", "Quotient.sound" ]
A dependent recursion principle for `Quotient`. It is analogous to the [recursor](lean-manual://section/recursors) for a structure, and can be used when the resulting type is not necessarily a proposition. While it is very general, this recursor can be tricky to use. The following simpler alternatives may be easier to...
2,088
2,094
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
recOnSubsingleton [h : (a : α) → Subsingleton (motive (Quotient.mk s a))] (q : Quotient s) (f : (a : α) → motive (Quotient.mk s a)) : motive q := Quot.recOnSubsingleton (h := h) q f
recOnSubsingleton [h : (a : α) → Subsingleton (motive (Quotient.mk s a))] (q : Quotient s) (f : (a : α) → motive (Quotient.mk s a)) : motive q
Quot.recOnSubsingleton (h := h) q f
abbrev
Quotient.recOnSubsingleton
Init
src/Init/Core.lean
[]
[ "Quot.recOnSubsingleton", "Quotient", "Quotient.mk", "Subsingleton" ]
An alternative recursion or induction principle for quotients that can be used when the target type is a subsingleton, in which all elements are equal. In these cases, the proof that the function respects the quotient's equivalence relation is trivial, so any function can be lifted. `Quotient.rec` does not assume tha...
2,105
2,111
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
hrecOn (q : Quotient s) (f : (a : α) → motive (Quotient.mk s a)) (c : (a b : α) → (p : a ≈ b) → f a ≍ f b) : motive q := Quot.hrecOn q f c
hrecOn (q : Quotient s) (f : (a : α) → motive (Quotient.mk s a)) (c : (a b : α) → (p : a ≈ b) → f a ≍ f b) : motive q
Quot.hrecOn q f c
abbrev
Quotient.hrecOn
Init
src/Init/Core.lean
[]
[ "Quot.hrecOn", "Quotient", "Quotient.mk" ]
A dependent recursion principle for `Quotient` that uses [heterogeneous equality](lean-manual://section/HEq), analogous to a [recursor](lean-manual://section/recursors) for a structure. `Quotient.recOn` is a version of this recursor that uses `Eq` instead of `HEq`.
2,120
2,126
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
lift₂ (f : α → β → φ) (c : (a₁ : α) → (b₁ : β) → (a₂ : α) → (b₂ : β) → a₁ ≈ a₂ → b₁ ≈ b₂ → f a₁ b₁ = f a₂ b₂) (q₁ : Quotient s₁) (q₂ : Quotient s₂) : φ := by apply Quotient.lift (fun (a₁ : α) => Quotient.lift (f a₁) (fun (a b : β) => c a₁ a a₁ b (Setoid.refl a₁)) q₂) _ q₁ intros induction q₂ using...
lift₂ (f : α → β → φ) (c : (a₁ : α) → (b₁ : β) → (a₂ : α) → (b₂ : β) → a₁ ≈ a₂ → b₁ ≈ b₂ → f a₁ b₁ = f a₂ b₂) (q₁ : Quotient s₁) (q₂ : Quotient s₂) : φ
by apply Quotient.lift (fun (a₁ : α) => Quotient.lift (f a₁) (fun (a b : β) => c a₁ a a₁ b (Setoid.refl a₁)) q₂) _ q₁ intros induction q₂ using Quotient.ind apply c; assumption; apply Setoid.refl
abbrev
Quotient.lift₂
Init
src/Init/Core.lean
[]
[ "Quotient", "Quotient.ind", "Quotient.lift", "Setoid.refl" ]
Lifts a binary function from the underlying types to a binary function on quotients. The function must respect both quotients' equivalence relations. `Quotient.lift` is a version of this operation for unary functions. `Quotient.liftOn₂` is a version that take the quotient parameters first.
2,141
2,149
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
liftOn₂ (q₁ : Quotient s₁) (q₂ : Quotient s₂) (f : α → β → φ) (c : (a₁ : α) → (b₁ : β) → (a₂ : α) → (b₂ : β) → a₁ ≈ a₂ → b₁ ≈ b₂ → f a₁ b₁ = f a₂ b₂) : φ := Quotient.lift₂ f c q₁ q₂
liftOn₂ (q₁ : Quotient s₁) (q₂ : Quotient s₂) (f : α → β → φ) (c : (a₁ : α) → (b₁ : β) → (a₂ : α) → (b₂ : β) → a₁ ≈ a₂ → b₁ ≈ b₂ → f a₁ b₁ = f a₂ b₂) : φ
Quotient.lift₂ f c q₁ q₂
abbrev
Quotient.liftOn₂
Init
src/Init/Core.lean
[]
[ "Quotient", "Quotient.lift₂" ]
Lifts a binary function from the underlying types to a binary function on quotients. The function must respect both quotients' equivalence relations. `Quotient.liftOn` is a version of this operation for unary functions. `Quotient.lift₂` is a version that take the quotient parameters last.
2,158
2,164
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
ind₂ {motive : Quotient s₁ → Quotient s₂ → Prop} (h : (a : α) → (b : β) → motive (Quotient.mk s₁ a) (Quotient.mk s₂ b)) (q₁ : Quotient s₁) (q₂ : Quotient s₂) : motive q₁ q₂ := by induction q₁ using Quotient.ind induction q₂ using Quotient.ind apply h
ind₂ {motive : Quotient s₁ → Quotient s₂ → Prop} (h : (a : α) → (b : β) → motive (Quotient.mk s₁ a) (Quotient.mk s₂ b)) (q₁ : Quotient s₁) (q₂ : Quotient s₂) : motive q₁ q₂
by induction q₁ using Quotient.ind induction q₂ using Quotient.ind apply h
theorem
Quotient.ind₂
Init
src/Init/Core.lean
[]
[ "Quotient", "Quotient.ind", "Quotient.mk" ]
null
2,166
2,175
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
inductionOn₂ {motive : Quotient s₁ → Quotient s₂ → Prop} (q₁ : Quotient s₁) (q₂ : Quotient s₂) (h : (a : α) → (b : β) → motive (Quotient.mk s₁ a) (Quotient.mk s₂ b)) : motive q₁ q₂ := by induction q₁ using Quotient.ind induction q₂ using Quotient.ind apply h
inductionOn₂ {motive : Quotient s₁ → Quotient s₂ → Prop} (q₁ : Quotient s₁) (q₂ : Quotient s₂) (h : (a : α) → (b : β) → motive (Quotient.mk s₁ a) (Quotient.mk s₂ b)) : motive q₁ q₂
by induction q₁ using Quotient.ind induction q₂ using Quotient.ind apply h
theorem
Quotient.inductionOn₂
Init
src/Init/Core.lean
[]
[ "Quotient", "Quotient.ind", "Quotient.mk" ]
null
2,177
2,186
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
inductionOn₃ {s₃ : Setoid φ} {motive : Quotient s₁ → Quotient s₂ → Quotient s₃ → Prop} (q₁ : Quotient s₁) (q₂ : Quotient s₂) (q₃ : Quotient s₃) (h : (a : α) → (b : β) → (c : φ) → motive (Quotient.mk s₁ a) (Quotient.mk s₂ b) (Quotient.mk s₃ c)) : motive q₁ q₂ q₃ := by induction q₁ using Quo...
inductionOn₃ {s₃ : Setoid φ} {motive : Quotient s₁ → Quotient s₂ → Quotient s₃ → Prop} (q₁ : Quotient s₁) (q₂ : Quotient s₂) (q₃ : Quotient s₃) (h : (a : α) → (b : β) → (c : φ) → motive (Quotient.mk s₁ a) (Quotient.mk s₂ b) (Quotient.mk s₃ c)) : motive q₁ q₂ q₃
by induction q₁ using Quotient.ind induction q₂ using Quotient.ind induction q₃ using Quotient.ind apply h
theorem
Quotient.inductionOn₃
Init
src/Init/Core.lean
[]
[ "Quotient", "Quotient.ind", "Quotient.mk", "Setoid" ]
null
2,188
2,200
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
rel {s : Setoid α} (q₁ q₂ : Quotient s) : Prop := Quotient.liftOn₂ q₁ q₂ (fun a₁ a₂ => a₁ ≈ a₂) (fun _ _ _ _ a₁b₁ a₂b₂ => propext (Iff.intro (fun a₁a₂ => Setoid.trans (Setoid.symm a₁b₁) (Setoid.trans a₁a₂ a₂b₂)) (fun b₁b₂ => Setoid.trans a₁b₁ (Setoid.trans b₁b₂ (Setoid.symm a₂b₂)))))
rel {s : Setoid α} (q₁ q₂ : Quotient s) : Prop
Quotient.liftOn₂ q₁ q₂ (fun a₁ a₂ => a₁ ≈ a₂) (fun _ _ _ _ a₁b₁ a₂b₂ => propext (Iff.intro (fun a₁a₂ => Setoid.trans (Setoid.symm a₁b₁) (Setoid.trans a₁a₂ a₂b₂)) (fun b₁b₂ => Setoid.trans a₁b₁ (Setoid.trans b₁b₂ (Setoid.symm a₂b₂)))))
def
Quotient.rel
Init
src/Init/Core.lean
[]
[ "Quotient", "Quotient.liftOn₂", "Setoid", "Setoid.symm", "Setoid.trans", "propext" ]
null
2,208
2,214
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
rel.refl {s : Setoid α} (q : Quotient s) : rel q q := q.inductionOn Setoid.refl
rel.refl {s : Setoid α} (q : Quotient s) : rel q q
q.inductionOn Setoid.refl
theorem
Quotient.rel.refl
Init
src/Init/Core.lean
[]
[ "Quotient", "Setoid", "Setoid.refl" ]
null
2,216
2,217
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
rel_of_eq {s : Setoid α} {q₁ q₂ : Quotient s} : q₁ = q₂ → rel q₁ q₂ := fun h => Eq.ndrecOn h (rel.refl q₁)
rel_of_eq {s : Setoid α} {q₁ q₂ : Quotient s} : q₁ = q₂ → rel q₁ q₂
fun h => Eq.ndrecOn h (rel.refl q₁)
theorem
Quotient.rel_of_eq
Init
src/Init/Core.lean
[]
[ "Quotient", "Setoid" ]
null
2,219
2,220
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
exact {s : Setoid α} {a b : α} : Quotient.mk s a = Quotient.mk s b → a ≈ b := fun h => rel_of_eq h
exact {s : Setoid α} {a b : α} : Quotient.mk s a = Quotient.mk s b → a ≈ b
fun h => rel_of_eq h
theorem
Quotient.exact
Init
src/Init/Core.lean
[]
[ "Quotient.mk", "Setoid" ]
If two values are equal in a quotient, then they are related by its equivalence relation.
2,225
2,226
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
recOnSubsingleton₂ {motive : Quotient s₁ → Quotient s₂ → Sort uC} [s : (a : α) → (b : β) → Subsingleton (motive (Quotient.mk s₁ a) (Quotient.mk s₂ b))] (q₁ : Quotient s₁) (q₂ : Quotient s₂) (g : (a : α) → (b : β) → motive (Quotient.mk s₁ a) (Quotient.mk s₂ b)) : motive q₁ q₂ := by induction q₁...
recOnSubsingleton₂ {motive : Quotient s₁ → Quotient s₂ → Sort uC} [s : (a : α) → (b : β) → Subsingleton (motive (Quotient.mk s₁ a) (Quotient.mk s₂ b))] (q₁ : Quotient s₁) (q₂ : Quotient s₂) (g : (a : α) → (b : β) → motive (Quotient.mk s₁ a) (Quotient.mk s₂ b)) : motive q₁ q₂
by induction q₁ using Quot.recOnSubsingleton induction q₂ using Quot.recOnSubsingleton apply g intro a; apply s induction q₂ using Quot.recOnSubsingleton intro a; apply s infer_instance
abbrev
Quotient.recOnSubsingleton₂
Init
src/Init/Core.lean
[]
[ "Quot.recOnSubsingleton", "Quotient", "Quotient.mk", "Subsingleton" ]
An alternative induction or recursion operator for defining binary operations on quotients that can be used when the target type is a subsingleton. In these cases, the proof that the function respects the quotient's equivalence relation is trivial, so any function can be lifted.
2,242
2,256
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Quotient.decidableEq {α : Sort u} {s : Setoid α} [d : ∀ (a b : α), Decidable (a ≈ b)] : DecidableEq (Quotient s) := fun (q₁ q₂ : Quotient s) => Quotient.recOnSubsingleton₂ q₁ q₂ fun a₁ a₂ => match d a₁ a₂ with | isTrue h₁ => isTrue (Quotient.sound h₁) | isFalse h₂ => isFalse fun...
Quotient.decidableEq {α : Sort u} {s : Setoid α} [d : ∀ (a b : α), Decidable (a ≈ b)] : DecidableEq (Quotient s)
fun (q₁ q₂ : Quotient s) => Quotient.recOnSubsingleton₂ q₁ q₂ fun a₁ a₂ => match d a₁ a₂ with | isTrue h₁ => isTrue (Quotient.sound h₁) | isFalse h₂ => isFalse fun h => absurd (Quotient.exact h) h₂
instance
Quotient.decidableEq
Init
src/Init/Core.lean
[]
[ "Decidable", "DecidableEq", "Quotient", "Quotient.exact", "Quotient.recOnSubsingleton₂", "Quotient.sound", "Setoid", "absurd" ]
null
2,261
2,268
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
funext {α : Sort u} {β : α → Sort v} {f g : (x : α) → β x} (h : ∀ x, f x = g x) : f = g := by let eqv (f g : (x : α) → β x) := ∀ x, f x = g x let extfunApp (f : Quot eqv) (x : α) : β x := Quot.liftOn f (fun (f : ∀ (x : α), β x) => f x) (fun _ _ h => h x) change extfunApp (Quot.mk eqv f) = extf...
funext {α : Sort u} {β : α → Sort v} {f g : (x : α) → β x} (h : ∀ x, f x = g x) : f = g
by let eqv (f g : (x : α) → β x) := ∀ x, f x = g x let extfunApp (f : Quot eqv) (x : α) : β x := Quot.liftOn f (fun (f : ∀ (x : α), β x) => f x) (fun _ _ h => h x) change extfunApp (Quot.mk eqv f) = extfunApp (Quot.mk eqv g) exact congrArg extfunApp (Quot.sound h)
theorem
funext
Init
src/Init/Core.lean
[]
[ "Quot.liftOn", "Quot.sound", "congrArg" ]
**Function extensionality.** If two functions return equal results for all possible arguments, then they are equal. It is called “extensionality” because it provides a way to prove two objects equal based on the properties of the underlying mathematical functions, rather than based on the syntax used to denote them. F...
2,281
2,289
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Quot.pliftOn {α : Sort u} {r : α → α → Prop} (q : Quot r) (f : (a : α) → q = Quot.mk r a → β) (h : ∀ (a b : α) (h h'), r a b → f a h = f b h') : β := q.rec (motive := fun q' => q = q' → β) f (fun a b p => funext fun h' => (apply_eqRec (motive := fun b _ => q = b)).trans (@h a b (h'.trans...
Quot.pliftOn {α : Sort u} {r : α → α → Prop} (q : Quot r) (f : (a : α) → q = Quot.mk r a → β) (h : ∀ (a b : α) (h h'), r a b → f a h = f b h') : β
q.rec (motive := fun q' => q = q' → β) f (fun a b p => funext fun h' => (apply_eqRec (motive := fun b _ => q = b)).trans (@h a b (h'.trans (sound p).symm) h' p)) rfl
abbrev
Quot.pliftOn
Init
src/Init/Core.lean
[]
[ "apply_eqRec", "funext", "rfl" ]
Like `Quot.liftOn q f h` but allows `f a` to "know" that `q = Quot.mk r a`.
2,294
2,301
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Quotient.pliftOn {α : Sort u} {s : Setoid α} (q : Quotient s) (f : (a : α) → q = Quotient.mk s a → β) (h : ∀ (a b : α) (h h'), a ≈ b → f a h = f b h') : β := Quot.pliftOn q f h
Quotient.pliftOn {α : Sort u} {s : Setoid α} (q : Quotient s) (f : (a : α) → q = Quotient.mk s a → β) (h : ∀ (a b : α) (h h'), a ≈ b → f a h = f b h') : β
Quot.pliftOn q f h
abbrev
Quotient.pliftOn
Init
src/Init/Core.lean
[]
[ "Quot.pliftOn", "Quotient", "Quotient.mk", "Setoid" ]
Like `Quotient.liftOn q f h` but allows `f a` to "know" that `q = Quotient.mk s a`.
2,306
2,310
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Pi.instSubsingleton {α : Sort u} {β : α → Sort v} [∀ a, Subsingleton (β a)] : Subsingleton (∀ a, β a) where allEq f g := funext fun a => Subsingleton.elim (f a) (g a)
Pi.instSubsingleton {α : Sort u} {β : α → Sort v} [∀ a, Subsingleton (β a)] : Subsingleton (∀ a, β a) where allEq f g := funext fun a => Subsingleton.elim (f a) (g a)
instance
Pi.instSubsingleton
Init
src/Init/Core.lean
[]
[ "Subsingleton", "Subsingleton.elim", "funext" ]
null
2,312
2,314
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
equivalence_true (α : Sort u) : Equivalence fun _ _ : α => True := ⟨fun _ => trivial, fun _ => trivial, fun _ _ => trivial⟩
equivalence_true (α : Sort u) : Equivalence fun _ _ : α => True
⟨fun _ => trivial, fun _ => trivial, fun _ _ => trivial⟩
theorem
equivalence_true
Init
src/Init/Core.lean
[]
[ "Equivalence", "True", "trivial" ]
null
2,318
2,319
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Setoid.trivial (α : Sort u) : Setoid α := ⟨_, equivalence_true α⟩
Setoid.trivial (α : Sort u) : Setoid α
⟨_, equivalence_true α⟩
def
Setoid.trivial
Init
src/Init/Core.lean
[]
[ "Setoid", "equivalence_true" ]
Always-true relation as a `Setoid`.
2,322
2,323
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Squash (α : Sort u) := Quotient (Setoid.trivial α)
Squash (α : Sort u)
Quotient (Setoid.trivial α)
def
Squash
Init
src/Init/Core.lean
[]
[ "Quotient", "Setoid.trivial" ]
The quotient of `α` by the universal relation. The elements of `Squash α` are those of `α`, but all of them are equal and cannot be distinguished. `Squash α` is a `Subsingleton`: it is empty if `α` is empty, otherwise it has just one element. It is the “universal `Subsingleton`” mapped from `α`. `Nonempty α` also has...
2,342
2,342
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Squash.mk {α : Sort u} (x : α) : Squash α := Quot.mk _ x
Squash.mk {α : Sort u} (x : α) : Squash α
Quot.mk _ x
def
Squash.mk
Init
src/Init/Core.lean
[]
[ "Squash" ]
Places a value into its squash type, in which it cannot be distinguished from any other.
2,347
2,347
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Squash.ind {α : Sort u} {motive : Squash α → Prop} (h : ∀ (a : α), motive (Squash.mk a)) : ∀ (q : Squash α), motive q := Quot.ind h
Squash.ind {α : Sort u} {motive : Squash α → Prop} (h : ∀ (a : α), motive (Squash.mk a)) : ∀ (q : Squash α), motive q
Quot.ind h
theorem
Squash.ind
Init
src/Init/Core.lean
[]
[ "Squash", "Squash.mk" ]
A reasoning principle that allows proofs about squashed types to assume that all values are constructed with `Squash.mk`.
2,353
2,354
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Squash.lift {α β} [Subsingleton β] (s : Squash α) (f : α → β) : β := Quot.lift f (fun _ _ _ => Subsingleton.elim _ _) s
Squash.lift {α β} [Subsingleton β] (s : Squash α) (f : α → β) : β
Quot.lift f (fun _ _ _ => Subsingleton.elim _ _) s
def
Squash.lift
Init
src/Init/Core.lean
[]
[ "Squash", "Subsingleton", "Subsingleton.elim" ]
Extracts a squashed value into any subsingleton type. If `β` is a subsingleton, a function `α → β` cannot distinguish between elements of `α` and thus automatically respects the universal relation that `Squash` quotients with.
2,362
2,363
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
: Subsingleton (Squash α) where allEq a b := by induction a using Squash.ind induction b using Squash.ind apply Quot.sound trivial
: Subsingleton (Squash α) where allEq a b := by induction a using Squash.ind induction b using Squash.ind apply Quot.sound trivial
instance
Init
src/Init/Core.lean
[]
[ "Quot.sound", "Squash", "Squash.ind", "Subsingleton", "trivial" ]
null
2,365
2,370
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
trustCompiler : True
trustCompiler : True
axiom
Lean.trustCompiler
Init
src/Init/Core.lean
[]
[ "True" ]
Depends on the correctness of the Lean compiler, interpreter, and all `[implemented_by ...]` and `[extern ...]` annotations.
2,378
2,379
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
reduceBool (b : Bool) : Bool := -- This ensures that `#print axioms` will track use of `reduceBool`. have := trustCompiler b
reduceBool (b : Bool) : Bool
-- This ensures that `#print axioms` will track use of `reduceBool`. have := trustCompiler b
opaque
Lean.reduceBool
Init
src/Init/Core.lean
[]
[ "Bool" ]
When the kernel tries to reduce a term `Lean.reduceBool c`, it will invoke the Lean interpreter to evaluate `c`. The kernel will not use the interpreter if `c` is not a constant. This feature is useful for performing proofs by reflection. Remark: the Lean frontend allows terms of the from `Lean.reduceBool t` where `t`...
2,401
2,405
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
reduceNat (n : Nat) : Nat := -- This ensures that `#print axioms` will track use of `reduceNat`. have := trustCompiler n
reduceNat (n : Nat) : Nat
-- This ensures that `#print axioms` will track use of `reduceNat`. have := trustCompiler n
opaque
Lean.reduceNat
Init
src/Init/Core.lean
[]
[ "Nat" ]
Similar to `Lean.reduceBool` for closed `Nat` terms. Remark: we do not have plans for supporting a generic `reduceValue {α} (a : α) : α := a`. The main issue is that it is non-trivial to convert an arbitrary runtime object back into a Lean expression. We believe `Lean.reduceBool` enables most interesting applications ...
2,415
2,419
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
ofReduceBool (a b : Bool) (h : reduceBool a = b) : a = b
ofReduceBool (a b : Bool) (h : reduceBool a = b) : a = b
axiom
Lean.ofReduceBool
Init
src/Init/Core.lean
[]
[ "Bool" ]
The axiom `ofReduceBool` is used to perform proofs by reflection. See `reduceBool`. This axiom is usually not used directly, because it has some syntactic restrictions. Instead, the `native_decide` tactic can be used to prove any proposition whose decidability instance can be evaluated to `true` using the lean compile...
2,436
2,437
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
ofReduceNat (a b : Nat) (h : reduceNat a = b) : a = b
ofReduceNat (a b : Nat) (h : reduceNat a = b) : a = b
axiom
Lean.ofReduceNat
Init
src/Init/Core.lean
[]
[ "Nat" ]
The axiom `ofReduceNat` is used to perform proofs by reflection. See `reduceBool`. Warning: by using this feature, the Lean compiler and interpreter become part of your trusted code base. This is extra 30k lines of code. More importantly, you will probably not be able to check your development using external type chec...
2,449
2,450
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
opaqueId {α : Sort u} (x : α) : α := x
opaqueId {α : Sort u} (x : α) : α
x
opaque
Lean.opaqueId
Init
src/Init/Core.lean
[]
[]
The term `opaqueId x` will not be reduced by the kernel.
2,456
2,456
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
ge_iff_le [LE α] {x y : α} : x ≥ y ↔ y ≤ x := Iff.rfl
ge_iff_le [LE α] {x y : α} : x ≥ y ↔ y ≤ x
Iff.rfl
theorem
ge_iff_le
Init
src/Init/Core.lean
[]
[ "Iff.rfl", "LE" ]
null
2,460
2,460
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
gt_iff_lt [LT α] {x y : α} : x > y ↔ y < x := Iff.rfl
gt_iff_lt [LT α] {x y : α} : x > y ↔ y < x
Iff.rfl
theorem
gt_iff_lt
Init
src/Init/Core.lean
[]
[ "Iff.rfl", "LT" ]
null
2,462
2,462
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
le_of_eq_of_le {a b c : α} [LE α] (h₁ : a = b) (h₂ : b ≤ c) : a ≤ c := h₁ ▸ h₂
le_of_eq_of_le {a b c : α} [LE α] (h₁ : a = b) (h₂ : b ≤ c) : a ≤ c
h₁ ▸ h₂
theorem
le_of_eq_of_le
Init
src/Init/Core.lean
[]
[ "LE" ]
null
2,464
2,464
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
le_of_le_of_eq {a b c : α} [LE α] (h₁ : a ≤ b) (h₂ : b = c) : a ≤ c := h₂ ▸ h₁
le_of_le_of_eq {a b c : α} [LE α] (h₁ : a ≤ b) (h₂ : b = c) : a ≤ c
h₂ ▸ h₁
theorem
le_of_le_of_eq
Init
src/Init/Core.lean
[]
[ "LE" ]
null
2,466
2,466
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
lt_of_eq_of_lt {a b c : α} [LT α] (h₁ : a = b) (h₂ : b < c) : a < c := h₁ ▸ h₂
lt_of_eq_of_lt {a b c : α} [LT α] (h₁ : a = b) (h₂ : b < c) : a < c
h₁ ▸ h₂
theorem
lt_of_eq_of_lt
Init
src/Init/Core.lean
[]
[ "LT" ]
null
2,468
2,468
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
lt_of_lt_of_eq {a b c : α} [LT α] (h₁ : a < b) (h₂ : b = c) : a < c := h₂ ▸ h₁
lt_of_lt_of_eq {a b c : α} [LT α] (h₁ : a < b) (h₂ : b = c) : a < c
h₂ ▸ h₁
theorem
lt_of_lt_of_eq
Init
src/Init/Core.lean
[]
[ "LT" ]
null
2,470
2,470
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Associative (op : α → α → α) : Prop where /-- An associative operation satisfies `(a ∘ b) ∘ c = a ∘ (b ∘ c)`. -/ assoc : (a b c : α) → op (op a b) c = op a (op b c)
Associative (op : α → α → α) : Prop where /-- An associative operation satisfies `(a ∘ b) ∘ c = a ∘ (b ∘ c)`. -/ assoc : (a b c : α) → op (op a b) c = op a (op b c)
class
Std.Associative
Init
src/Init/Core.lean
[]
[]
`Associative op` indicates `op` is an associative operation, i.e. `(a ∘ b) ∘ c = a ∘ (b ∘ c)`.
2,479
2,481
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Commutative (op : α → α → α) : Prop where /-- A commutative operation satisfies `a ∘ b = b ∘ a`. -/ comm : (a b : α) → op a b = op b a
Commutative (op : α → α → α) : Prop where /-- A commutative operation satisfies `a ∘ b = b ∘ a`. -/ comm : (a b : α) → op a b = op b a
class
Std.Commutative
Init
src/Init/Core.lean
[]
[]
`Commutative op` says that `op` is a commutative operation, i.e. `a ∘ b = b ∘ a`.
2,487
2,489
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
IdempotentOp (op : α → α → α) : Prop where /-- An idempotent operation satisfies `a ∘ a = a`. -/ idempotent : (x : α) → op x x = x
IdempotentOp (op : α → α → α) : Prop where /-- An idempotent operation satisfies `a ∘ a = a`. -/ idempotent : (x : α) → op x x = x
class
Std.IdempotentOp
Init
src/Init/Core.lean
[]
[]
`IdempotentOp op` indicates `op` is an idempotent binary operation. i.e. `a ∘ a = a`.
2,495
2,497
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
LeftIdentity (op : α → β → β) (o : outParam α) : Prop
LeftIdentity (op : α → β → β) (o : outParam α) : Prop
class
Std.LeftIdentity
Init
src/Init/Core.lean
[]
[ "outParam" ]
`LeftIdentity op o` indicates `o` is a left identity of `op`. This class does not require a proof that `o` is an identity, and is used primarily for inferring the identity using class resolution.
2,505
2,505
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
LawfulLeftIdentity (op : α → β → β) (o : outParam α) : Prop extends LeftIdentity op o where /-- Left identity `o` is an identity. -/ left_id : ∀ a, op o a = a
LawfulLeftIdentity (op : α → β → β) (o : outParam α) : Prop extends LeftIdentity op o where /-- Left identity `o` is an identity. -/ left_id : ∀ a, op o a = a
class
Std.LawfulLeftIdentity
Init
src/Init/Core.lean
[]
[ "outParam" ]
`LawfulLeftIdentity op o` indicates `o` is a verified left identity of `op`.
2,511
2,513
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
RightIdentity (op : α → β → α) (o : outParam β) : Prop
RightIdentity (op : α → β → α) (o : outParam β) : Prop
class
Std.RightIdentity
Init
src/Init/Core.lean
[]
[ "outParam" ]
`RightIdentity op o` indicates `o` is a right identity `o` of `op`. This class does not require a proof that `o` is an identity, and is used primarily for inferring the identity using class resolution.
2,521
2,521
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
LawfulRightIdentity (op : α → β → α) (o : outParam β) : Prop extends RightIdentity op o where /-- Right identity `o` is an identity. -/ right_id : ∀ a, op a o = a
LawfulRightIdentity (op : α → β → α) (o : outParam β) : Prop extends RightIdentity op o where /-- Right identity `o` is an identity. -/ right_id : ∀ a, op a o = a
class
Std.LawfulRightIdentity
Init
src/Init/Core.lean
[]
[ "outParam" ]
`LawfulRightIdentity op o` indicates `o` is a verified right identity of `op`.
2,527
2,529
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Identity (op : α → α → α) (o : outParam α) : Prop extends LeftIdentity op o, RightIdentity op o
Identity (op : α → α → α) (o : outParam α) : Prop extends LeftIdentity op o, RightIdentity op o
class
Std.Identity
Init
src/Init/Core.lean
[]
[ "outParam" ]
`Identity op o` indicates `o` is a left and right identity of `op`. This class does not require a proof that `o` is an identity, and is used primarily for inferring the identity using class resolution.
2,537
2,537
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
LawfulIdentity (op : α → α → α) (o : outParam α) : Prop extends Identity op o, LawfulLeftIdentity op o, LawfulRightIdentity op o
LawfulIdentity (op : α → α → α) (o : outParam α) : Prop extends Identity op o, LawfulLeftIdentity op o, LawfulRightIdentity op o
class
Std.LawfulIdentity
Init
src/Init/Core.lean
[]
[ "outParam" ]
`LawfulIdentity op o` indicates `o` is a verified left and right identity of `op`.
2,543
2,543
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
LawfulCommIdentity (op : α → α → α) (o : outParam α) [hc : Commutative op] : Prop extends LawfulIdentity op o where left_id a := Eq.trans (hc.comm o a) (right_id a) right_id a := Eq.trans (hc.comm a o) (left_id a)
LawfulCommIdentity (op : α → α → α) (o : outParam α) [hc : Commutative op] : Prop extends LawfulIdentity op o where left_id a := Eq.trans (hc.comm o a) (right_id a) right_id a := Eq.trans (hc.comm a o) (left_id a)
class
Std.LawfulCommIdentity
Init
src/Init/Core.lean
[]
[ "Eq.trans", "outParam" ]
`LawfulCommIdentity` can simplify defining instances of `LawfulIdentity` on commutative functions by requiring only a left or right identity proof. This class is intended for simplifying defining instances of `LawfulIdentity` and functions needed commutative operations with identity should just add a `LawfulIdentity` ...
2,554
2,556
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
: Commutative Or := ⟨fun _ _ => propext or_comm⟩
: Commutative Or
⟨fun _ _ => propext or_comm⟩
instance
Init
src/Init/Core.lean
[]
[ "Or", "propext" ]
null
2,558
2,558
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
: Commutative And := ⟨fun _ _ => propext and_comm⟩
: Commutative And
⟨fun _ _ => propext and_comm⟩
instance
Init
src/Init/Core.lean
[]
[ "And", "propext" ]
null
2,559
2,559
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
: Commutative Iff := ⟨fun _ _ => propext iff_comm⟩
: Commutative Iff
⟨fun _ _ => propext iff_comm⟩
instance
Init
src/Init/Core.lean
[]
[ "Iff", "propext" ]
null
2,560
2,560
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Refl (r : α → α → Prop) : Prop where /-- A reflexive relation satisfies `r a a`. -/ refl : ∀ a, r a a
Refl (r : α → α → Prop) : Prop where /-- A reflexive relation satisfies `r a a`. -/ refl : ∀ a, r a a
class
Std.Refl
Init
src/Init/Core.lean
[]
[]
`Refl r` means the binary relation `r` is reflexive, that is, `r x x` always holds.
2,563
2,565
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Antisymm (r : α → α → Prop) : Prop where /-- An antisymmetric relation `r` satisfies `r a b → r b a → a = b`. -/ antisymm (a b : α) : r a b → r b a → a = b
Antisymm (r : α → α → Prop) : Prop where /-- An antisymmetric relation `r` satisfies `r a b → r b a → a = b`. -/ antisymm (a b : α) : r a b → r b a → a = b
class
Std.Antisymm
Init
src/Init/Core.lean
[]
[]
`Antisymm r` says that `r` is antisymmetric, that is, `r a b → r b a → a = b`.
2,568
2,570
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Asymm (r : α → α → Prop) : Prop where /-- An asymmetric relation satisfies `r a b → ¬ r b a`. -/ asymm : ∀ a b, r a b → ¬r b a
Asymm (r : α → α → Prop) : Prop where /-- An asymmetric relation satisfies `r a b → ¬ r b a`. -/ asymm : ∀ a b, r a b → ¬r b a
class
Std.Asymm
Init
src/Init/Core.lean
[]
[]
`Asymm r` means that the binary relation `r` is asymmetric, that is, `r a b → ¬ r b a`.
2,573
2,575
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Symm (r : α → α → Prop) : Prop where /-- A symmetric relation satisfies `r a b → r b a`. -/ symm : ∀ a b, r a b → r b a
Symm (r : α → α → Prop) : Prop where /-- A symmetric relation satisfies `r a b → r b a`. -/ symm : ∀ a b, r a b → r b a
class
Std.Symm
Init
src/Init/Core.lean
[]
[]
`Symm r` means that the binary relation `r` is symmetric, that is, `r a b → r b a`.
2,578
2,580
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Total (r : α → α → Prop) : Prop where /-- A total relation satisfies `r a b` or `r b a`. -/ total : ∀ a b, r a b ∨ r b a
Total (r : α → α → Prop) : Prop where /-- A total relation satisfies `r a b` or `r b a`. -/ total : ∀ a b, r a b ∨ r b a
class
Std.Total
Init
src/Init/Core.lean
[]
[]
`Total X r` means that the binary relation `r` on `X` is total, that is, `r a b` or `r b a`.
2,583
2,585
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Irrefl (r : α → α → Prop) : Prop where /-- An irreflexive relation satisfies `¬ r a a`. -/ irrefl : ∀ a, ¬r a a
Irrefl (r : α → α → Prop) : Prop where /-- An irreflexive relation satisfies `¬ r a a`. -/ irrefl : ∀ a, ¬r a a
class
Std.Irrefl
Init
src/Init/Core.lean
[]
[]
`Irrefl r` means the binary relation `r` is irreflexive, that is, `r x x` never holds.
2,588
2,590
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
Trichotomous (r : α → α → Prop) : Prop where /-- An trichotomous relation `r` satisfies `¬ r a b → ¬ r b a → a = b`. -/ trichotomous (a b : α) : ¬ r a b → ¬ r b a → a = b
Trichotomous (r : α → α → Prop) : Prop where /-- An trichotomous relation `r` satisfies `¬ r a b → ¬ r b a → a = b`. -/ trichotomous (a b : α) : ¬ r a b → ¬ r b a → a = b
class
Std.Trichotomous
Init
src/Init/Core.lean
[]
[]
`Trichotomous r` says that `r` is trichotomous, that is, `¬ r a b → ¬ r b a → a = b`.
2,593
2,595
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
flip_flip {α : Sort u} {β : Sort v} {φ : Sort w} {f : α → β → φ} : flip (flip f) = f := by apply funext intro a apply funext intro b rw [flip, flip]
flip_flip {α : Sort u} {β : Sort v} {φ : Sort w} {f : α → β → φ} : flip (flip f) = f
by apply funext intro a apply funext intro b rw [flip, flip]
theorem
flip_flip
Init
src/Init/Core.lean
[]
[ "flip", "funext" ]
null
2,599
2,605
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
TypeNameData (α : Type u) : NonemptyType.{0} := ⟨Name, inferInstance⟩
TypeNameData (α : Type u) : NonemptyType.{0}
⟨Name, inferInstance⟩
opaque
TypeNameData
Init
src/Init/Dynamic.lean
[ "Init.Core" ]
[]
null
19
20
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
TypeName (α : Type u) where private mk' :: private data : (TypeNameData α).type
TypeName (α : Type u) where private mk' :: private data : (TypeNameData α).type
class
TypeName
Init
src/Init/Dynamic.lean
[ "Init.Core" ]
[ "TypeNameData" ]
Dynamic type name information. Types with an instance of `TypeName` can be stored in an `Dynamic`. The type class contains the declaration name of the type, which must not have any universe parameters and be of type `Sort ..` (i.e., monomorphic). The preferred way to declare instances of this type is using the derive ...
38
40
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
: Nonempty (TypeName α) := by exact (TypeNameData α).property.elim (⟨⟨·⟩⟩)
: Nonempty (TypeName α)
by exact (TypeNameData α).property.elim (⟨⟨·⟩⟩)
instance
Init
src/Init/Dynamic.lean
[ "Init.Core" ]
[ "Nonempty", "TypeName", "TypeNameData" ]
null
42
42
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
TypeName.mk (α : Type u) (typeName : Name) : TypeName α := ⟨unsafeCast typeName⟩
TypeName.mk (α : Type u) (typeName : Name) : TypeName α
⟨unsafeCast typeName⟩
def
TypeName.mk
Init
src/Init/Dynamic.lean
[ "Init.Core" ]
[ "TypeName" ]
Creates a `TypeName` instance. For safety, it is required that the constant `typeName` is definitionally equal to `α`.
50
52
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
TypeName.typeNameImpl (α) [TypeName α] : Name := unsafeCast (@TypeName.data α _)
TypeName.typeNameImpl (α) [TypeName α] : Name
unsafeCast (@TypeName.data α _)
def
TypeName.typeNameImpl
Init
src/Init/Dynamic.lean
[ "Init.Core" ]
[ "TypeName", "unsafeCast" ]
null
54
55
true
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6
TypeName.typeName (α) [TypeName α] : Name
TypeName.typeName (α) [TypeName α] : Name
opaque
TypeName.typeName
Init
src/Init/Dynamic.lean
[ "Init.Core" ]
[ "TypeName" ]
Returns a declaration name of the type.
60
61
false
https://github.com/leanprover/lean4
d265d1ca745e7741a7e7f7366c22ce9c9dda57b6