<span class="hljs-keyword">structure</span> <span class="hljs-type">List</span> : <span class="hljs-type">LIST</span> =
  <span class="hljs-keyword">struct</span>

    <span class="hljs-keyword">val</span> <span class="hljs-keyword">op</span> +  = <span class="hljs-type">InlineT</span>.<span class="hljs-type">DfltInt</span>.+

    <span class="hljs-keyword">datatype</span> <span class="hljs-built_in">list</span> = <span class="hljs-keyword">datatype</span> <span class="hljs-built_in">list</span>

    <span class="hljs-keyword">exception</span> <span class="hljs-type">Empty</span> = <span class="hljs-type">Empty</span>

    <span class="hljs-keyword">fun</span> last <span class="hljs-literal">[]</span> = <span class="hljs-keyword">raise</span> <span class="hljs-type">Empty</span>
      | last [x] = x
      | last (_::r) = last r

  <span class="hljs-keyword">fun</span> loop (<span class="hljs-literal">[]</span>, <span class="hljs-literal">[]</span>) = <span class="hljs-type">EQUAL</span>
    | loop (<span class="hljs-literal">[]</span>, _) = <span class="hljs-type">LESS</span>
    | loop (_, <span class="hljs-literal">[]</span>) = <span class="hljs-type">GREATER</span>
    | loop (x :: xs, y :: ys) =
      (<span class="hljs-keyword">case</span> compare (x, y) <span class="hljs-keyword">of</span>
     <span class="hljs-type">EQUAL</span> =&gt; loop (xs, ys)
         | unequal =&gt; unequal)
    <span class="hljs-keyword">in</span>
  loop
    <span class="hljs-keyword">end</span>

  <span class="hljs-keyword">end</span> <span class="hljs-comment">(* structure List *)</span>