*     ************************************************************************

      subroutine sxcon(xstat)

*     ************************************************************************

*     Purpose :
*     ---------

*     This routine modifies the status XSTAT to correspond to the
*     status of a nonbasic variable that has already been used
*     for de-activation.

*     The fourth bit of the integer XSTAT is set to one.

*     Parameter :
*     -----------

*     xstat

*       input  : the status of the considered variable.
*       output : the updated status corresponds to the
*                status of nonbasic variable that has
*                already been used for de-activation.

*     Routines used :
*     ---------------

*     None.

*     Programming :
*     -------------

*     D. Tuyttens 

*     ========================================================================

*     Routine parameter

      integer  xstat

*     Internal variable

      integer  aux

      aux = xstat / 8
      if( mod(aux,2).eq.0 ) xstat = xstat + 8

      return
      end