fact: Definition Build_IsInitialMorphism (A : D) (p : morphism C X (U A)) (Ap := CommaCategory.Build_object !X U tt A p) (UniversalProperty : forall (A' : D) (p' : morphism C X (U A')), Contr { m : morphism D A A' | U _1 m o p = p' }) : IsInitialMorphism Ap.
imports: Category.Core Functor.Core Category.Dual Functor.Dual Category.Objects InitialTerminalCategory.Core InitialTerminalCategory.Functors Trunc Types.Sigma HoTT.Tactics Basics.Tactics