anchor.diff:  
     <div class="container">
       <h1>
  -      <% group['prefix_pairs'].each do |prefix, combined| %>
  -      <a href="<%= combined.join('.') %>.html"><%= prefix %></a>
  -      <% end %>
  +<code>
  +      <% group['prefix_pairs'].each_with_index do |(prefix, combined), i| %><%= if i > 0 then "." end %><a href="<%= combined.join('.') %>.html"><%= prefix %></a><% end %>
  +</code>
       </h1>
   
  -    <h2><%= group['doc'] %></h2>
  +    <p><%= group['doc'] %></p>
  +
  +    <% unless group['subitems'].empty? %>
   
       <ul>
         <% group['subitems'].each do |item| %>
  
positive.code: 
      <% group['subitems'].each do |item| %>
  
      <a name="<%= item['name'] %>"></a>
      <h3><a href="#<%= item['name'] %>"><%= item['name'] %></a></h3>
      <code><%= item['def'] %></code>
      <p><%= item['doc'] %></p>
  
      <% end %>
  
      <h2>Submodules</h2>
  
      <% if ! group['subgroups'].empty? %>
  
      <ul>
        <% group['subgroups'].each do |subgroup| %>
  
negative.code:       <% end %>
      </ul>
  
      <% end %>
  
    </div>
  