Ex­ten­sive Ar­rows. – Ex­tra Ar­rows be­yond those pro­vided in AMS­math

Ar­rows are pro­vided to sup­ple­ment \xlef­t­ar­row and \xrightar­row of the AMSMath pack­age: \xlonge­qual, \xLon­glef­t­ar­row, \xLon­grightar­row, \xLon­gleft­rightar­row, \xLeftrightar­row. \xlon­gleft­rightar­row, \xleft­rightar­row, \xlon­glef­t­ar­row and \xlon­grightar­row.