Definition BDDsharing_OK (bs : BDDstate) (share : BDDsharing_map) :=
    forall (x : BDDvar) (l r a : ad),
    BDDshare_lookup share x l r = Some a <->
    MapGet _ bs a = Some (x, (l, r)).

(* Specifications: *)
Lemma initBDDsharing_map_OK : BDDsharing_OK initBDDstate initBDDsharing_map.