[css-pseudo-4] Fix fictional tag sequence example error.

Author: fantasai

css-pseudo-4/Overview.bs

@@ -226,18 +226,18 @@ Inheritance and the ''::first-line'' Pseudo-element</h4>
       The first line will be styled
       by the ‘::first-line’ pseudo-element.
       The other lines will be treated
-      as ordinary lines in the paragraph.&lt;/P&gt;
+      as ordinary lines in the paragraph.&lt;/p&gt;
     </pre>
 
     And in the case of the second rendering:
 
     <pre class="lang-markup">
-      &lt;P&gt;<strong>&lt;p::first-line></strong>This is a somewhat long<strong>&lt;/p::first-line></strong> HTML paragraph
+      &lt;p&gt;<strong>&lt;p::first-line></strong>This is a somewhat long<strong>&lt;/p::first-line></strong> HTML paragraph
       that will be broken into several lines.
       The first line will be styled
       by the ‘::first-line’ pseudo-element.
       The other lines will be treated
-      as ordinary lines in the paragraph.&lt;/P&gt;
+      as ordinary lines in the paragraph.&lt;/p&gt;
     </pre>
   </div>
 
@@ -251,24 +251,24 @@ Inheritance and the ''::first-line'' Pseudo-element</h4>
     with a <code>span</code> element encompassing the first sentence:
 
     <pre class="lang-markup">
-      &lt;P&gt;<strong>&lt;span></strong>This is a somewhat long HTML paragraph
+      &lt;p&gt;<strong>&lt;span></strong>This is a somewhat long HTML paragraph
       that will be broken into several lines.<strong>&lt;/span></strong>
       The first line will be styled
       by the ‘::first-line’ pseudo-element.
       The other lines will be treated
-      as ordinary lines in the paragraph.&lt;/P&gt;
+      as ordinary lines in the paragraph.&lt;/p&gt;
     </pre>
 
     The effect of the first rendering
     would be similar to the following [=fictional tag sequence=]:
 
     <pre class="lang-markup">
-      &lt;P&lt;P&gt;<strong>&lt;p::first-line>&lt;span></strong>This is a somewhat long HTML paragraph
-      that<strong>&lt;/span>&lt;/P&gt;&lt;p::first-line>&lt;span></strong> will be broken into several lines.<strong>&lt;/span></strong>
+      &lt;p&gt;<strong>&lt;p::first-line>&lt;span></strong>This is a somewhat long HTML paragraph
+      that<strong>&lt;/span>&lt;/p::first-line>&lt;span></strong> will be broken into several lines.<strong>&lt;/span></strong>
       The first line will be styled
       by the ‘::first-line’ pseudo-element.
       The other lines will be treated
-      as ordinary lines in the paragraph.&lt;/P&gt;
+      as ordinary lines in the paragraph.&lt;/p&gt;
     </pre>
   </div>