use strict;
use warnings;

sub print_power_of_2 {
    my $x = shift;

    my $result = power_of_2();
    print "$x^2 = $result\n";

    sub power_of_2 { return $x ** 2; }
}

print_power_of_2(5);
print_power_of_2(6);

##</code><code>##

sub print_power_of_2 {
    my $x = shift;

    my $result = power_of_2();
    print "$x^2 = $result\n";

    my $power_of_2 = sub { return $x ** 2; };
}