Module ESF2 := FSetFacts.Facts(EqSet2).Module ESP2 := FSetProperties.Properties(EqSet2).Module ESD2 := FSetDecide.Decide(EqSet2).

Lemma in_subst_loc: forall l1 l2 q (e e': eqs), EqSet.In q e -> subst_loc l1 l2 e = Some e' -> (eloc q = l1 /\ EqSet.In (Eq (ekind q) (ereg q) l2) e') \/ (Loc.diff l1 (eloc q) /\ EqSet.In q e').