sub closure {
    my $a = $_[0];
    return sub { $a += 2 };
}

my $first = closure(1);

print $first->(), "\n"; # 3
print $first->(), "\n"; # 5

my $second = closure(14);

print $second->(), "\n"; # 16
print $first->(), "\n"; # 7

##</code><code>##

2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$