xbmtopbm contractArrow.xbm    >contractArrow.pbm
xbmtopbm contractOnArrow.xbm  >contractOnArrow.pbm
xbmtopbm emptyArrow.xbm       >emptyArrow.pbm
xbmtopbm expandArrow.xbm      >expandArrow.pbm
xbmtopbm expandOnArrow.xbm    >expandOnArrow.pbm
