fact: Definition double_transport {C : precategory_ob_mor} {a a' b b' : ob C} (p : a = a') (q : b = b') (f : a --> b) : a' --> b' := transportf (λ c, a' --> c) q (transportf (λ c, c --> b) p f).
imports: UniMath.Foundations.PartA UniMath.Foundations.Sets UniMath.MoreFoundations.PartA UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos