# Test list concatenation operator ++
let
  list1 = [1 2 3];
  list2 = [4 5 6];
  empty = [];
in {
  # Basic concatenation
  combined = list1 ++ list2;

  # Concatenate with empty list
  with_empty = list1 ++ empty;

  # Nested concatenation
  triple = [1] ++ [2] ++ [3];
}