fact: Definition law' : functor' o inverse' = 1 /\ inverse' o functor' = 1 := center _.
imports: HoTT.Basics HoTT.Types Category.Core Functor.Core InitialTerminalCategory.Core InitialTerminalCategory.Functors Category.Prod Functor.Prod Functor.Composition.Core Functor.Identity Functor.Composition.Laws