rlapped
    {
      background-color: red;
      z-index: 2;
    }

  div#green-overlapping
    {
      background-color: green;
      z-index: calc(3 / 2);
      /*
      should resolve to 'z-index: 2' since "values
      halfway between adjacent integers rounded
      towards positive infinity" and since
      div#green-overlapping is last in document
      tree order, then it should overlap
      div#red-overlapped
      */
    }
  </style>

  <p>Test passes if there is a filled green square and <strong>