use strict;
use warnings;

sub funcs {
        my $a = 0;
        return ( sub { $a++ }, sub { $a } );
}

my ( $f11, $f12 ) = funcs();
my ( $f21, $f22 ) = funcs();
print join( " ", $f11->(), $f12->(), $f22->() ), "\n"; #prints "0 1 0"