, 6 * emToPx, epsilon, "mundeover");

          element = document.getElementById("core_operator_5");
          assert_approx_equals(element.getBoundingClientRect().height, 6 * emToPx, epsilon, "complex nesting");
      }, `Embellished operators`);

      done();
  }
</script>
</head>
<body>
  <div id="log"></div>
  <p>
    <math>
      <mrow>
        <mspace width="1em" height="3em" depth="3em" style="background: blue"/>
        <mo id="horizontal_arrow" stretchy="true">⥚</mo>
        <mo id="vertical_ar