proposition: Lemma extract_andp_ocon_ocon_left {A} {JA : Join A} {PA : Perm_alg A} {SA: Sep_alg A}{AG : ageable A} {AA : Age_alg A}: forall (w : A) P Q R S, (P && Q ⊗ R ⊗ S) w -> exists w', P w'.
proof: Proof. repeat intro; destruct_ocon H h; destruct_ocon H2 i; destruct H6; exists i12; trivial. Qed.
imports: VST.msl.msl_standard VST.msl.corable CertiGraph.msl_ext.ramify_tactics CertiGraph.msl_ext.msl_ext CertiGraph.msl_ext.sepalg