use strict;
use warnings;

my @dotted_stuff
    = (
       q(),
       '1.A',
       '12.1',
       '1.9',
       '01.9',
       '1.9.1',
       '1.9.2.1',
       '12.1.1',
       '12.13',
   );

for my $va (@dotted_stuff) {
    for my $vb (@dotted_stuff) {
        printf qq(%-7s and %-7s => ), $va, $vb;
        if ($va =~ m{ \A (\d+) \. (\d+) }xms) {
            my ($a1, $a2) = ($1, $2);
            if ($vb =~ m{ \A (\d+) \. (\d+) }xms) {
                my ($b1, $b2) = ($1, $2);
                if ($a1 == $b1 and $a2 == $b2) {
                    print "MATCH!\n";
                    next;
                }
            }
        }
        print "no match.\n";
    }
}
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