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