name extarrows category Package shortdesc Extra Arrows beyond those provided in AMS math longdesc Arrows are provided to supplement \xleftarrow and \xrightarrow of longdesc teh AMSMath package: \xlongequal \xLongleftarrow \xLongrightarrow longdesc \xLongleftrightarrow \xLeftrightarrow \xlongleftrightarrow longdesc \xleftrightarrow \xlongleftarrow \xlongrightarrow [description longdesc copied from TeX Catalogue]