, "span");
  assert_equals(element.namespaceURI, HTMLNS);
  assert_equals(element.prefix, null);
  assert_equals(element.localName, "span");
  assert_equals(element.tagName, "SPAN");
  assert_true(element instanceof Node, "Should be a Node");
  assert_true(element instanceof Element, "Should be an Element");
  assert_true(element instanceof HTMLElement, "Should be an HTMLElement");
  assert_true(element instanceof HTMLSpanElement, "Should be an HTMLSpanElement");
}, "Lower-case HTML element without a prefix