anchor.diff:                                           :id,
                                            :name) do |box| %>
       <li>
  -      <%= box.check_box(disabled: @person.and_descendants.include?(box.object)).concat(box.label) %>
  +      <%= box.check_box(
  +                disabled: @person.and_descendants.include?(box.object) ||
  +                            @person.new_record?
  +              ).concat(box.label) %>
       </li>
       <% end %>
     </ul>
  
positive.code:     <% end %>
      <p><%= link_to_add_fields "Add Phone", person_form, :phones %></p>
    </ul>
    <h3>Children</h3>
    <ul>
      <%= person_form.collection_check_boxes(:child_ids,
  
negative.code:       :id,
        :name) do |box| %>
        <li>
          <%= box.check_box(
                    disabled: @person.and_ancestors.include?(box.object) ||
                                @person.new_record?
                  ).concat(box.label) %>
        </li>
      <% end %>
    </ul>
  