Yes, thanks. I had to convince myself again - it's been a long time since I last used it.

my $s_1 = Set::Scalar->new(split//, "abc");
my $s_2 = Set::Scalar->new(split//, "aaaaaabc");

dd $s_1;
dd $s_2;

__END__

do {
  my $a = bless({
    elements => { a => "a", b => "b", c => "c" },
    universe => bless({
                  elements => { a => "a", b => "b", c => "c" },
                  null => bless({ universe => 'fix' }, "Set::Scalar::N
+ull"),
                  universe => undef,
                }, "Set::Scalar::Universe"),
  }, "Set::Scalar");
  $a->{universe}{null}{universe} = $a->{universe};
  $a;
}
do {
  my $a = bless({
    elements => { a => "a", b => "b", c => "c" },
    universe => bless({
                  elements => { a => "a", b => "b", c => "c" },
                  null => bless({ universe => 'fix' }, "Set::Scalar::N
+ull"),
                  universe => undef,
                }, "Set::Scalar::Universe"),
  }, "Set::Scalar");
  $a->{universe}{null}{universe} = $a->{universe};
  $a;
}
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