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 distrib_sepcon_andp {A} {JA: Join A}{PA: Perm_alg A}: forall P Q R, P * (Q && R) |-- (P * Q) && (P * R).