10 lines
291 B
Text
10 lines
291 B
Text
open eq tactic
|
|
open eq (rec_on)
|
|
|
|
definition concat_whisker2 {A} {x y z : A} (p p' : x = y) (q q' : y = z) (a : p = p') (b : q = q') :
|
|
(whiskerR a q) ⬝ (whiskerL p' b) = (whiskerL p b) ⬝ (whiskerR a q') :=
|
|
begin
|
|
apply (rec_on b),
|
|
apply (rec_on a),
|
|
apply ((concat_1p _)⁻¹),
|
|
end
|