msubsupBase").right, getBox("msubsupSub").left, e, "msubsup: subscript is after base");
      assert_approx_equals(getBox("msubsupBase").right, getBox("msubsupSup").left, e, "msubsup: superscript is after base");
    }, "Respective horizontal positions");

    test(function() {
      assert_true(MathMLFeatureDetection.has_mspace());

      var e = 1;
      assert_approx_equals(getBox("msubBase").middle, getBox("baseline").bottom, e, "msub: base is placed on the baseline");
      assert_approx_equals(getBox(