2014-08-25 02:58:48 +00:00
|
|
|
import logic
|
2014-07-03 17:50:08 +00:00
|
|
|
using tactic
|
|
|
|
|
|
|
|
variable A : Type.{1}
|
|
|
|
variable f : A → A → A
|
|
|
|
|
|
|
|
theorem tst {a b c : A} (H1 : a = b) (H2 : b = c) : f a b = f b c
|
|
|
|
:= by apply (@congr A A);
|
|
|
|
apply (subst H2);
|
|
|
|
apply refl;
|
|
|
|
assumption
|