fact: Definition fam_to_slice_mor {a b : fam X} (f : a --> b) : f_to_s a --> f_to_s b := (λ h, pr1 h ,, (pr1 f) (pr1 h) (pr2 h)) ,, (idpath (pr2 (f_to_s a))).
imports: UniMath.Foundations.Sets UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Categories.HSET.Core UniMath.CategoryTheory.Categories.HSET.MonoEpiIso UniMath.CategoryTheory.Categories.HSET.Univalence UniMath.CategoryTheory.Categories.HSET.Slice UniMath.CategoryTheory.slicecat UniMath.CategoryTheory.Adjunctions.Core UniMath.CategoryTheory.Equivalences.Core UniMath.CategoryTheory.FunctorCategory UniMath.CategoryTheory.Groupoids UniMath.CategoryTheory.Categories.StandardCategories