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;
reserve D,D1,D2 for NonatomicND of V,A;

theorem Th39:
  x in ND(V,A) implies x is TypeSCNominativeData of V,A
  proof
    assume x in ND(V,A);
    then ex D being TypeSCNominativeData of V,A st x = D;
    hence thesis;
  end;
