al(getBox("msubsupBase").right, getBox("msubsupSup").left, e, "msubsup: superscript is after base");

      e = 3;
      assert_approx_equals(getBox("msubBase").right, getBox("msubSub").left, e, "msub: space between base and subscript is small");
      assert_approx_equals(getBox("msubBase").right, getBox("msubSub").left, e, "msub: subscript is after base");
      assert_approx_equals(getBox("msupBase").right, getBox("msupSup").left, e, "msup: superscript is after base");
      assert_approx_equals(getBox("