Definition wk_split {A} {JA: Join A} :=
forall a b c d e : A, join a b c -> join d e c -> joins a d -> join_sub d b.

Lemma ewand_TT_sepcon {T}{agT:ageable T}{JT: Join T}{PT: Perm_alg T}{ST: Sep_alg T}{AT: Age_alg T}:
forall P Q R,
(P * Q && ewand R (!!True))%pred |-- (P && ewand R (!!True) * (Q && ewand R (!!True)))%pred.