proposition: Proposition internal_pre_post_comp_id (x y : V) : internal_pre_post_comp (identity x) (identity y) = identity _.
proof: Proof. rewrite internal_pre_post_comp_as_pre_post_comp. rewrite internal_precomp_id. rewrite internal_postcomp_id. rewrite id_left. apply idpath. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.FunctorCategory UniMath.CategoryTheory.Adjunctions.Core UniMath.CategoryTheory.Monoidal.WhiskeredBifunctors UniMath.CategoryTheory.Monoidal.Categories UniMath.CategoryTheory.Monoidal.Structure.Symmetric