Definition corable {A} {JA: Join A}{PA: Perm_alg A}{SA: Sep_alg A}
         (P: pred A) := forall w, P w = P (core w).

Lemma corable_andp_sepcon1{A} {JA: Join A}{PA: Perm_alg A}{SA: Sep_alg A}: forall P Q R, corable P -> (P && Q) * R = P && (Q * R).