Hint Rewrite @pure_sepcon_TT_andp @pure_sepcon_TT_andp' using (solve [auto]): normalize.

Lemma pull_right0 {A}  {JA: Join A}{PA: Perm_alg A}{SA: Sep_alg A}{agA: ageable A}{AgeA: Age_alg A}: forall P Q,
(P * Q) = (Q * P).