N == 4;

  W == max(0, (available-width - ((N - 1) * column-gap)) / N);
  W == max(0, (15em - ((4 - 1) * 1em)) / 4);
  W == max(0, (15em - (3 * 1em)) / 4);
  W == max(0, (15em - (3em)) / 4);
  W == max(0, (12em) / 4);
  W == max(0, 3em);
  W == 3em;

  */

  /*
  Since column rules do not take up space, then the test
  should not generate an horizontal scrollbar.
  */
  ]]></style>
 </head>

 <body>

  <div>
  1s cl
  2n cl
  3r cl
  4t cl
  </div>

 </body>
</html>
