use overload '0+' => \#
sub num { print "[$_[0]->[0]]"; return $_[0]->[0]; }

##</code><code>##

[1][1]1 == 1
1 != 3
1 != 4
[1][3]3 != 1
3 == 3
3 != 4
[1][4]4 != 1
4 != 3
4 == 4