Local Open Scope logic.
Module VericSepLogic <: SepTheory.SepTheory.
Definition hprop := mpred.
Definition himp := derives.
Definition heq := fun p1 p2 => derives p1 p2 /\ derives p2 p1.
Definition Refl_himp := derives_refl.
Definition Trans_himp := derives_trans.

Lemma Sym_heq : Symmetric heq.