anchor.diff:      <p class='CodeRay'>
         <pre>
           <p class='code'>
  -          <span class='command-prompt'>proc contents data=</span><span>cloud._all_;</span>
  +          <span class='command-prompt'>proc contents data=</span><span class='command-entry'>cloud._all_;</span>
             <span class='command-prompt'>run;</span>
           </p>
         </pre>
  
positive.code:         <span class='command-prompt'>   cloud            </span><span class='command-response'> /* my libref  */</span>
          <span class='command-prompt'>   postgres         </span><span class='command-response'> /* postgres engine  */</span>
          <% if user_signed_in? %>
          <span class='command-prompt'>   user=</span><span>"<%= current_user.username %>"     </span><span class='command-response'> /* supply your login credentials  */</span>
          <% else %>
          <span class='command-prompt'>   user=</span><span class='command-note'> (sign up/in to get a username) </span><span class='command-response'> /* supply your login credentials  */</span>
          <% end %>
          <span class='command-prompt'>   database=</span><span>"<%= ENV["AACT_PUBLIC_DATABASE_NAME"] %>"</span>
          <span class='command-prompt'>   server=</span><span>"<%= ENV["AACT_PUBLIC_HOSTNAME"] %>"</span>
          <span class='command-prompt'>   port=</span><span>5432</span>
          <span class='command-prompt'>   dbmax_text=</span><span>32767 </span><span class='command-response'> /* sets the length of long text variables */</span>
          <span class='command-prompt'>   preserve_tab_names=</span><span>yes</span>
          <span class='command-prompt'>   access=</span><span>readonly</span>
          <span class='command-prompt'>;</span>
        </p>
        </pre>
  
negative.code:       <pre>
          <p class='code'>
            <span class='command-prompt'>title 'Number of studies by type';</span>
            <span class='command-prompt'>proc freq data=</span><span class='command-entry'>cloud.studies;</span>
            <span class='command-prompt'>   tables </span><span class='command-entry'>study_type;</span>
            <span class='command-prompt'>   run;</span>
            <span class='command-prompt'>title;</span>
        </p>
  