Hint Resolve type_defs_incr: ty.

(* Specifications: *)
Lemma type_defs_sound:
forall te xl tyl e e', type_defs e xl tyl = OK e' -> satisf te e' -> list_forall2 T.sub tyl (map te xl).
Lemma type_use_incr:
forall te x ty e e', type_use e x ty = OK e' -> satisf te e' -> satisf te e.