, "single3 not checked [after single2 checked]");
  assert_false(single3.matches(":checked"),
      "single3 not :checked [after single2 checked]");

  single3.checked = true;
  assert_false(single1.checked, "single1 not checked [after single3 checked]");
  assert_false(single1.matches(":checked"),
      "single1 not :checked [after single3 checked]");
  assert_false(single2.checked, "single2 not checked [after single3 checked]");
  assert_false(single2.matches(":checked"),
      "single2 not :checked [afte