~cpp
   begin real procedure A(k, x1, x2, x3, x4, x5);
     value k; integer k;
     begin real procedure B;
       begin k := k - 1;
             B := A := A(k, B, x1, x2, x3, x4)
       end;
       if k <= 0 then A := x4 + x5 else B
     end;
   end;
   outreal(A(10, 1, -1, -1, 1, 0));