fact: Record object := { a : A; b : B; f : Functor (S a) (T b) }.
imports: Category.Core Functor.Core NaturalTransformation.Core Functor.Composition.Core NaturalTransformation.Paths NaturalTransformation.Composition.Core Category.Morphisms FunctorCategory.Core Pseudofunctor.Core NaturalTransformation.Composition.Laws Trunc Types.Sigma Basics.Tactics