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

Lemma pure_sepcon1' {A} {JA: Join A}{PA: Perm_alg A}{SA: Sep_alg A}{agA: ageable A}{AgeA: Age_alg A}:
forall P Q R, pure P -> P * Q |-- P * R -> P * Q |-- R.