{A : Type} (B C : A -> Type) {x1 x2 : A} (p : x1 = x2) (f : B x1 -> C x1) (g : B x2 -> C x2) (h : forall (y1 : B x1), transport C p (f y1) = g (transport B p y1)) (u : B x1) : ap10 (dpath_arrow B C p f g h) (p # u) = transport_arrow p f (p # u) @ ap (fun x => p # (f x)) (transport_Vp B p u) @ h u. Proof. destruct p; simpl; unfold ap10. exact (apD10_path_forall f g h u @ (concat_1p _)^). Defined.
Require Import Basics.Overture Basics.PathGroupoids Basics.Decidable Require Import Types.Forall.