Arguments bind_rule [W A B e1 e2 i].

(* Same lemma for unary postconidtions *)
Lemma call_rule W A (p : Pred state) (q : A -> Pred state) i
{e} (k : cont A) :
(i \In Coh W -> p i) ->
(forall x m, q x m -> m \In Coh W -> k x m) ->
verify i (@with_spec this W A (binarify p q) e) k.