Section BasicRules.
Variable this : nid.

(* An inference rule for the sequential composition *)
Lemma bind_rule W A B (e1 : DT this W A) (e2 : A -> DT this W B) i
(q : cont A) (r : cont B) :
verify i e1 q ->
(forall y j, q y j -> j \In Coh W  -> verify j (e2 y) r) ->
verify i (bind e1 e2) r.