This variant of [string] is: string is wideinteger ?-strict? ?-failindex ''varname''? '''stringArgument''' It returns a Boolean indicator as to whether its string argument is any of the valid forms for a wide integer in Tcl, with optional surrounding whitespace. In the case of under or overflow in the value, 0 is returned and varname, if provided as an argument to -failindex, will have a value of -1. [[Is there a wiki page that discusses the valid forms for a wide integer? If so, please replace this comment with the page reference. Thank you.]] <> Command