Section MapFoldResults.
Variable A : Type.
Variable M : Type.
Variable neutral : M.
Variable op : M -> M -> M.
Variable nleft : forall a:M, op neutral a = a.
Variable nright : forall a:M, op a neutral = a.
Variable assoc : forall a b c:M, op (op a b) c = op a (op b c).

Lemma MapFold_ext :
forall (f:ad -> A -> M) (m m':Map A),
eqmap A m m' -> MapFold _ _ neutral op f m = MapFold _ _ neutral op f m'.