Module WFacts_fun (E:DecidableType)(Import M:WSfun E).
Notation eq_dec := E.eq_dec.
Definition eqb x y := if eq_dec x y then true else false.

Lemma MapsTo_fun : forall (elt:Type) m x (e e':elt),
MapsTo x e m -> MapsTo x e' m -> e=e'.