Hint Resolve @corable_andp @corable_orp @corable_allp @corable_exp
@corable_imp @corable_prop @corable_sepcon @corable_wand @corable_later.
Hint Resolve @corable_prop : norm.
(* The followings are not in auto-rewrite lib. *)

Lemma prop_impl {A} {NA: NatDed A}:
forall P Q: Prop, prop (P -> Q) = (prop P --> prop Q).