proposition: Lemma Sum_η {X : HSET} (h : Sum → pr1hSet X) : Sum_rec (h ∘ Sum_inl) (h ∘ Sum_inr) = h.
proof: Proof. eapply pathscomp0. apply Sum_com_con. apply funextfun; intro s. simpl. apply maponpaths. apply Sum_weak_eta. Defined.
imports: UniMath.Foundations.Init UniMath.Foundations.Preamble UniMath.Foundations.PartA UniMath.Foundations.Sets UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.FunctorAlgebras UniMath.CategoryTheory.Categories.HSET.Core UniMath.CategoryTheory.Categories.HSET.Structures