fact: Definition unfunctor_sum_l {A A' B B' : Type} (h : A + B -> A' + B') (Ha : forall a:A, is_inl (h (inl a))) : A -> A' := fun a => un_inl (h (inl a)) (Ha a).
imports: HoTT.Basics Types.Empty Types.Unit Types.Prod Types.Sigma Types.Bool Types.Forall