reserve a,a1,a2,v,v1,v2,x for object;
reserve V,A for set;
reserve m,n for Nat;
reserve S,S1,S2 for FinSequence;

theorem
  NDSS(V,A) c= PFuncs(V,A)
  proof
    let x;
    assume x in NDSS(V,A);
    then ex w being TypeSSNominativeData of V,A st w = x;
    hence thesis by PARTFUN1:45;
  end;
