// First, we'll define a general-purpose zip() to zip
 any
// number of lists together.
function zip(...)
  {
    variable result := [];
    variable list_num := 0;
    iterate(arg; arguments)
      {
        variable elem_num := 0;
        iterate (x; arg)
          {
            if (elem_num >= length(result))
                result[elem_num] := <<(* --> "")>>;;
            result[elem_num][list_num] := x;
            ++elem_num;
          };
        ++list_num;
      };
    return result;
  };

immutable a := ["a", "b", "c"],
          b := ["A", "B", "C"],
          c := [1, 2, 3];
iterate (x; zip(a, b, c))
    print(x[0], x[1], x[2], "\n");;