diff --git a/templates/match.html.ep b/templates/match.html.ep
index 447ad32..99e6171 100644
--- a/templates/match.html.ep
+++ b/templates/match.html.ep
@@ -8,6 +8,7 @@
   <div>
     <div class="snippet"><%== $match->{snippet} %></div>
     <div class="tokenInfo"></div>
+%#    <div class="treeInfo"></div>
   </div>
   <p>
 % if ($match->{title}) {
@@ -25,7 +26,7 @@
 
 % }
     <li onclick="showTable(this)" title="Annotations"><i class="fa fa-info-circle"></i></li>
-%#    <li title="Tree Visualizations"><i class="fa fa-sitemap"></i></li>
+%#   <li onclick="showTree(this, 'xip', 'c')" title="Tree Visualizations"><i class="fa fa-sitemap"></i></li>
 %#    <li title="Remember"><i class="fa fa-star-o"></i></li>
   </ul>
 </li>
diff --git a/templates/partial/header.html.ep b/templates/partial/header.html.ep
index 2422819..a386f69 100644
--- a/templates/partial/header.html.ep
+++ b/templates/partial/header.html.ep
@@ -2,6 +2,7 @@
   <title><%= title %></title>
 %= asset 'korap.css'
 %= asset 'korap.js'
+
   <meta charset="utf-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0, user-scalable=false, user-scalable=no" />
 </head>
diff --git a/templates/query.html.ep b/templates/query.html.ep
index 0eebd0c..c1d3153 100644
--- a/templates/query.html.ep
+++ b/templates/query.html.ep
@@ -1,4 +1,5 @@
 % use JSON::XS;
+% use Mojo::JSON;
 
 % if (stash('search.query') && stash('test_port')) {
 %   my $action;
@@ -9,7 +10,8 @@
 <pre class="query serial<%== $action // '' %>">
   <span>JSON-LD Serialization for <%= param 'q' %> (<%= param 'ql' %>)</span>
   <code>
-<%= $json->encode(stash('search.query')) =%>
+%# Workaround to keep true, false, and null intact
+%= $json->encode($json->decode(Mojo::JSON::encode_json(stash('search.query'))))
   </code>
 </pre>
 %= javascript begin
diff --git a/templates/tutorial/poliqarp-plus.html.ep b/templates/tutorial/poliqarp-plus.html.ep
index e7017d4..e62b260 100644
--- a/templates/tutorial/poliqarp-plus.html.ep
+++ b/templates/tutorial/poliqarp-plus.html.ep
@@ -273,9 +273,9 @@
 
 %= korap_tut_query poliqarp => 'matches(<s>,[tt/p=CARD][tt/p="N.*"])', cutoff => 1
 
-<!--
-<p>overlaps()</p>
--->
+<p>The <code>overlaps()</code> operation will match, when a second subquery has an overlapping span with the first subquery.</p>
+
+%= korap_tut_query poliqarp => 'overlaps([][tt/p=ADJA],{1:[tt/p=ADJA]}[])', cutoff => 1
 
 <blockquote class="warning">
   <p>Positional operators are still experimental and may change in certain aspects in the future (although the behaviour defined is intended to be stable). There is also known incorrect behaviour which will be corrected in future versions.</p>
@@ -317,9 +317,9 @@
 
 %= korap_tut_query poliqarp => 'focus(der {[]} Mann)'
 
-<p>This will limit the match to all interesting terms in between &quot;der&quot; and &quot;Mann&quot;. Or you may want to search for all words following the sequence &quot;der alte und neue&quot;:</p>
+<p>This will limit the match to all interesting terms in between &quot;der&quot; and &quot;Mann&quot;. Or you may want to search for all words following the sequence &quot;der alte und&quot; immediately:</p>
 
-%= korap_tut_query poliqarp => 'focus(der alte und neue {[]})'
+%= korap_tut_query poliqarp => 'focus(der alte und {[]})'
 
 <!--
 <p><code>focus()</code> is especially useful if you are searching for matches in certain areas, for example in quotes using positional operators.