Yitzchak Scott-Thoennes wrote: > But of course: > > /^(?:(?:(\d+)-(?=(\d+)(??{$1 >= $2 && > "(?!)"})))?(\d+)(?:\z|,(?=(\d+)(??{$3 >= $4 && "(?!)"}))))+\z/ > Did you give Number::Range a shot? HTH, ~Y