recurse_lex(1);
print "\n";
recurse_lex(2);
print "\n";
recurse_lex(3);
print "\n";
recurse_lex(4);
print "\n";

sub recurse_lex {
  my $i = shift;
  my @array if 0;
  unshift @array, $i;
  print @array, "\n";
  $i--;
  if ($i) {
    recurse_lex($i);
  }
}