C*GRFLUN -- free a Fortran logical unit number (Sun/Convex-UNIX)
C+
      SUBROUTINE GRFLUN(LUN)
      INTEGER LUN
C
C Free a Fortran logical unit number allocated by GRGLUN. [This version
C does nothing.]
C
C Arguments:
C  LUN    : the logical unit number to free.
C--
C 25-Nov-1988
C-----------------------------------------------------------------------
      RETURN
      END
