anchor.diff:          <thead>
             <tr>
               <th class="title">Title</th>
  +            <% if exhibition_is_set %>
               <th class="artwork"># of Artwork</th>
  +            <% end %>
               <th class="actions"></th>
             </tr>
           </thead>
  
positive.code:           <% @categories.each do |category| %>
              <tr>
                <td class="title"><%= category.title %></td>
                <td class="artwork"><%= category.artworks.size %> <%= link_to('Show', exhibition_artworks_path(@exhibition, :filter_category => category.id), :class => 'btn btn-mini btn-info') %></td>
                <td class="actions"><%= link_to 'Show', [@exhibition, category], :class => 'btn btn-mini btn-info' %> <%= link_to 'Edit', edit_exhibition_category_path(@exhibition, category), :class => 'btn btn-mini' %> <%= link_to 'Delete', [@exhibition, category], method: :delete, data: { confirm: 'Are you sure?' }, :class => 'btn btn-mini btn-danger' %></td>
              </tr>
            <% end %>
  
negative.code:       <p><%= link_to 'New Category', new_exhibition_category_path(@exhibition), :class => 'btn btn-success' %></p>
      </div>
    </div>
  </div>
  