

          lvarpop var [index [string]]
               The lvarpop command pops (deletes) the element indexed
               by index from the list contained in the variable var.
               If index is omitted, then 0 is assumed.  If string, is
               specified, then the deleted element is replaced by
               string. The replaced or deleted element is returned.
               Thus ``lvarpop argv 0'' returns the first element of
               argv, setting argv to contain the remainder of the
               string.
