theorem
  global_overlapping(V,A,D,D) = D
  proof
    per cases;
    suppose
A1:   not D in A;
      dom D c= dom D;
      hence thesis by A1,Th65;
    end;
    suppose
A2:   D in A;
      D is TypeSCNominativeData of V,A by Def6;
      hence thesis by A2,Def16;
    end;
  end;
