{X} {a : X} (p q r : idpath a = idpath a) : eh (p @ q) r @ (concat_p_pp _ _ _ @ whiskerR (eh p r)^ _) = concat_pp_p _ _ _ @ whiskerL _ (eh q r) @ concat_p_pp _ _ _. Proof. nrapply eh_pp_p_gen. - exact (ulnat_pp p q). - exact (ulnat_pp p q). - exact (wlrnat_pp_p p q r). Defined.
From HoTT Require Import Basics Types.