  </p>

    <p>
      This function works by brute force, that is, it tries every
      possible subset to see if it sums to the desired value.
    </p>

    <p>
      Given N weights, every possible selection can be described by
      one of the N-digit binary numbers from 0 to 2^N-1.
    </p>

    <p>
      This function includes a range, which allows the user to
      control which subsets are to be checked.  Thus, if there are
      N weights, specifying a range of [ 0, 2^N-1] indicates that
      all s