(* Packaging the definition into an type, _indexed_ by a specificaion s. *)
Inductive DT (W: world) A :=
  with_spec (s : spec A) of DTbin this W s.(* Packaging the definition into an type, _indexed_ by a specificaion s. *)
Inductive DT (W: world) A :=
  with_spec (s : spec A) of DTbin this W s.

Lemma leq_trans e1 e2 e3 : leq e1 e2 -> leq e2 e3 -> leq e1 e3.