subroutine HexObj( mode, nnObj, x, fObj, gObj, nState, 
     &                   cu, lencu, iu, leniu, ru, lenru )

      implicit           double precision(a-h,o-z)
      double precision   x(nnObj), gObj(nnObj)

      character*8        cu(lencu)
      integer            iu(leniu)
      double precision   ru(lenru)

*     ==================================================================
*     Problem Hexagon.
*     No user-defined storage is used.
*     ==================================================================

      fObj    = - x(2)*x(6) + x(1)*x(7) - x(3)*x(7) - x(5)*x(8)
     &          + x(4)*x(9) + x(3)*x(8)

      gObj(1) =   x(7)
      gObj(2) = - x(6)
      gObj(3) = - x(7) + x(8)
      gObj(4) =   x(9)
      gObj(5) = - x(8)
      gObj(6) = - x(2)
      gObj(7) = - x(3) + x(1)
      gObj(8) = - x(5) + x(3)
      gObj(9) =   x(4)

*     end of objective for snmain.
      end