Section MapAxioms.
Variables A B C : Type.
Definition eqmap (m m':Map A) := eqm A (MapGet A m) (MapGet A m').
End MapAxioms.

Lemma MapDomRestrBy_m_m :
forall (A:Type) (m:Map A),
eqmap A (MapDomRestrBy A unit m (MapDom A m)) (M0 A).