fact: Definition property a b fo fm := (Category.axioms a) & (Category.axioms b) & (forall x, ob a x -> ob b (fo x)) & (forall x, ob a x -> id b (fo x) = fm (id a x)) & (forall u, mor a u -> mor b (fm u)) & (forall u, mor a u -> source (fm u) = fo (source u)) & (forall u, mor a u -> target (fm u) = fo (target u)) & (forall u v, mor a u -> mor a v -> source u = target v-> comp b (fm u) (fm v) = fm (comp a u v)).
imports: Arith category