fact: Definition transposcommsqstr {X X' Y Z : UU} (f : X -> Y) (f' : X' -> Y) (g : Z -> X) (g' : Z -> X') : commsqstr g' f' g f -> commsqstr g f g' f' := λ h : _, λ z : Z, (pathsinv0 (h z)).
imports: UniMath.Foundations.Preamble