proposition: Lemma idtoiso_postcompose (C : precategory) (a b b' : ob C) (p : b = b') (f : a --> b) : f · idtoiso p = transportf (λ b, a --> b) p f.
proof: Proof. destruct p. apply id_right. Qed.
imports: UniMath.Foundations.PartA UniMath.Foundations.Sets UniMath.MoreFoundations.PartA UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos