for $i (0..1) {
  for $j ($i+1..3) {
    for $k ($j+1..5) {
      for $l ($k+1..7) {

##</code><code>##

my $depth = 4;
my $loop = [[0..1]];
my $val = 3;
for my $i (1..$depth-1) {
    push @$loop, sub {[$_+1..$val]};
    $val+=2;
}
my $iter = NestedLoops($loop);
while (my @list = $iter->()) {
  output(@list);
}

sub output {
  my @args = @_;
  print join '', @args, "\n";
}

##</code><code>##

my $n = shift;
sub plustwo_iter {
  my $val = 1;
  return sub  {
    $val +=2;
    return $val;
  }
}

my $p = plustwo_iter();

my $loop = [[0..1], (sub {[$_+1..&$p]}) x ($n-2)];

my $iter = NestedLoops($loop);
while (my @list = $iter->()) {
  output(@list);
}