28 lines
475 B
Text
28 lines
475 B
Text
open nat
|
|
|
|
definition id [unfold-f] {A : Type} (a : A) := a
|
|
definition compose {A B C : Type} (g : B → C) (f : A → B) (a : A) := g (f a)
|
|
notation g ∘ f := compose g f
|
|
|
|
example (a b : nat) (H : a = b) : id a = b :=
|
|
begin
|
|
esimp,
|
|
state,
|
|
exact H
|
|
end
|
|
|
|
example (a b : nat) (H : a = b) : (id ∘ id) a = b :=
|
|
begin
|
|
esimp,
|
|
state,
|
|
exact H
|
|
end
|
|
|
|
attribute compose [unfold-f]
|
|
|
|
example (a b : nat) (H : a = b) : (id ∘ id) a = b :=
|
|
begin
|
|
esimp,
|
|
state,
|
|
exact H
|
|
end
|