Definition superprecise {A}  {JA: Join A}{PA: Perm_alg A}{SA: Sep_alg A} (P: pred A) :=
forall w1 w2, P w1 -> P w2 -> comparable w1 w2 -> w1=w2.

Lemma ewand_sepcon {A} {JA: Join A}{PA: Perm_alg A}: forall P Q R,
(ewand (P * Q) R = ewand P (ewand Q R))%pred.