note blakem I'm familiar with assigning to slices of a hash, and its use in this line:<P> <CODE>@seen {$t, $h, $r, $e} = ();</CODE><P> was very clever. However, why did you use slices in these lines?<P> <CODE> @seen {$n,} = (); .... @seen {$o,} = (); </CODE> Aren't they equivalent to:<BR> <CODE> $seen{$n} = undef; $seen{$o} = undef; </CODE> Or even just:<BR> <CODE> @seen {$n} = (); # note the lack of comma after $n .... @seen {$o} = (); </CODE> I guess its that trailing comma that looks odd to me.<P> -Blake<BR> p.s. props on the @HIGH and @LOW generation... very sneaky! 84175 84259