proposition: Corollary unit_triangle {a b c : C} (f : C⟦a, b⟧) (g : C⟦b, c⟧) : rassociator f (identity b) g • id2 f ⋆ lunitor g = runitor f ⋆ id2 g.
proof: Proof. unfold hcomp. rewrite id2_rwhisker. rewrite lwhisker_id2. rewrite id2_right. rewrite id2_left. apply lunitor_lwhisker. Qed.
imports: UniMath.Tactics.EnsureStructuredProofs UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.PrecategoryBinProduct