End MapCard.
Section MapCard2.
Variables A B : Type.

(* Specifications: *)
Lemma MapSubset_card_eq_1 :
forall (n:nat) (m:Map A) (m':Map B),
MapSubset _ _ m m' ->
MapCard _ m = n -> MapCard _ m' = n -> MapSubset _ _ m' m.
Lemma MapDomRestrTo_Card_ub_r :
forall (m:Map A) (m':Map B),
MapCard A (MapDomRestrTo A B m m') <= MapCard B m'.