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