lean2/examples/ex13.lean
Leonardo de Moura f886485056 Add new example
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2013-08-30 13:37:18 -07:00

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Variable f {A : Type} (a b : A) : A
Variable N : Type
Variable n1 : N
Variable n2 : N
Set lean::pp::implicit true
Show f n1 n2
Show f (fun x : N -> N, x) (fun y : _, y)
Variable EqNice {A : Type} (lhs rhs : A) : Bool
Infix 50 === : EqNice
Show n1 === n2
Check f n1 n2
Check Congr
Show f n1 n2
Theorem CongrI {A : Type u} {B : A → Type u} {f g : Π x : A, B x} {a b : A} (H1 : f = g) (H2 : a = b) : (f a) = (g b) :=
Congr A B f g a b H1 H2
Theorem TransI {A : Type u} {a b c : A} (H1 : a = b) (H2 : b = c) : a = c :=
Trans A a b c H1 H2
Theorem ReflI {A : Type u} (a : A) : a = a :=
Refl A a
Theorem SymmI {A : Type u} {a b : A} (H : a = b) : b = a :=
Symm A a b H
Theorem Conj1I {a b : Bool} (H : a && b) : a :=
Conjunct1 a b H
Theorem Conj2I {a b : Bool} (H : a && b) : b :=
Conjunct2 a b H
Variable a : N
Variable b : N
Variable c : N
Variable g : N -> N
Axiom H1 : a = b && b = c
Theorem Pr : (g a) = (g c) :=
CongrI (ReflI g) (TransI (Conj1I H1) (Conj2I H1))
Show Environment 1