fact: Definition property f g t := (Functor.axioms f) & (Functor.axioms g) & (source f) = (source g) & (target f) = (target g) & (forall x, ob (source f) x -> mor (target g) (t x)) & (forall x, ob (source f) x -> source (t x) = fob f x) & (forall x, ob (source f) x -> target (t x) = fob g x) & (forall u, mor (source f) u -> comp (target g) (t (target u)) (fmor f u) = comp (target g) (fmor g u) (t (source u))).
imports: Arith functor