
        <code class="type">anyrange</code> <code class="literal">-</code> <code class="type">anyrange</code>
        → <code class="returnvalue">anyrange</code>
       </p>
       <p>
        Computes the difference of the ranges.  The second range must not be
        contained in the first in such a way that the difference would not be
        a single range.
       </p>
       <p>
        <code class="literal">int8range(5,15) - int8range(10,20)</code>
        → <code class="returnvalue">[5,10)</code>