Section ListOfDomDef.
Variable A : Type.
Definition ad_list_of_dom :=
MapFold A (list ad) nil (app (A:=ad)) (fun (a:ad) (_:A) => a :: nil).

Lemma Elems_of_list_of_dom :
forall m:Map A, eqmap unit (Elems (ad_list_of_dom m)) (MapDom A m).