>> M = (3, 5, 9, [2, -3]); >> N = (1, -7, 0, [-2, 5]); >> M + N (4, -2, 9, [0, 2])The subtraction of one list from another list is defined similarly. If the lengths of the two lists are different, or if any two corresponding elements can not be added, then the addition of the two lists is undefined and attempt to it will cause an error.
Note that in some languages, adding two lists means concatenating them to make a longer list. In Shang, the operator for concatenating two lists is >-<.