fact: Definition square_pequiv_pfiber {A B C D} {f : A ->* B} {g : C ->* D} (h : A <~>* C) (k : B <~>* D) (p : k o* f ==* g o* h) : h o* pfib f ==* pfib g o* pequiv_pfiber h k p := square_functor_pfiber p.
imports: Basics Types WildCat HFiber Pointed.Core Pointed.pEquiv Pointed.Loops