reserve a,b,c,d,e,f for Real,
        g           for positive Real,
        x,y         for Complex,
        S,T         for Element of REAL 2,
        u,v,w       for Element of TOP-REAL 3;
reserve a,b,c for Element of F_Real,
          M,N for Matrix of 3,F_Real;
reserve D        for non empty set;
reserve d1,d2,d3 for Element of D;
reserve A        for Matrix of 1,3,D;
reserve B        for Matrix of 3,1,D;

theorem
  ex d1,d2,d3 st A = <* <* d1,d2,d3 *> *>
  proof
    A = <* <* A*(1,1), A*(1,2), A*(1,3) *> *> by Th26;
    hence thesis;
  end;
