# spot reverse ranges like 27..5
	 if ($range =~ /[^.]\.\.[^.]/){
		foreach my $match ( $range=~/(\d+\.\.\d+)/g ){
			$match=~/(\d+)\.\.(\d+)/;
			croak "$1 > $2 in range [$range]" if $1 > $2;
		}
	}