use 5.012;
use List::Util qw[min max];

for my $l (0..2) {
  for my $k (0..($l-1), ($l+1)..2) {
    my ($j1, $j2) = (min($l, $k), max($l, $k));
    for my $j (0..($j1-1), ($j1+1)..($j2-1), ($j2+1)..2) {
      say "l = $l, k = $k, j = $j";
    }
  }
}