proposition: Lemma FF_precise: forall {A} `{PreciseSepLog A}, precise FF.
proof: Proof. intros. apply derives_precise with emp. + apply FF_left. + apply precise_emp. Qed.
imports: VST.msl.Extensionality VST.msl.simple_CCC VST.msl.seplog VST.msl.log_normalize Coq.Lists.List CertiGraph.msl_ext.seplog CertiGraph.msl_ext.abs_addr