(* Constructions with lift **************************************************)
theorem ifr_lift_bi (f) (t1) (t2) (r):
- t1 โก๐ข๐[r] t2 โ โ[f]t1 โก๐ข๐[โ[f]r] โ[f]t2.
+ t1 โก๐ข๐[r] t2 โ ๐ ก[f]t1 โก๐ข๐[๐ ก[f]r] ๐ ก[f]t2.
#f #t1 #t2 #r
* #p #q #n #Hr #Hn #Ht1 #Ht2 destruct
-@(ex4_3_intro โฆ (โ[f]p) (โ[โ[pโ๐โ๐]f]q) ((โ[pโ๐โ๐โq]f)๏ผ ยงโจnโฉ))
+@(ex4_3_intro โฆ (๐ ก[f]p) (๐ ก[๐ ข[f](pโ๐โ๐)]q) (๐ ข[f](pโ๐โ๐โq)๏ผ ยงโจnโฉ))
[ -Hn -Ht1 -Ht2 //
| -Ht1 -Ht2
/2 width=1 by lift_path_rmap_closed_L/