fact: Definition inverse : Functor C (C * 1) := 1 * Functors.to_terminal _.
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