10 lines
323 B
Text
10 lines
323 B
Text
import logic data.string
|
|
|
|
constant A : Type.{1}
|
|
constant f : A → A → A
|
|
open eq
|
|
theorem tst {a b c : A} (H1 : a = b) (H2 : b = c) : f a (f b b) = f b (f c c)
|
|
:= by discard (apply (subst H1)) 3; -- discard the first 3 solutions produced by apply
|
|
trace "after subst H1";
|
|
apply (subst H2);
|
|
apply eq.refl
|