use warnings;
use strict;
use Set::IntSpan;
my $set = Set::IntSpan->new("1,2,5,6,9,10,41-56");
for my $x (1,2,3,42,100) {
	print "$x is ", $set->member($x)?"":"NOT ", "in the set\n";
}
__END__
1 is in the set
2 is in the set
3 is NOT in the set
42 is in the set
100 is NOT in the set