sub wow {
    my $x= my $y= shift @_;
    sub pow {
        return $y *= $x;
    }
}
wow($_) for 2, 3, 5;
print pow(), $/ for 1..3;
__END__
Variable "$y" will not stay shared at - line 4.
Variable "$x" will not stay shared at - line 4.
4
8
16