>>> within a paragraph
Within a <em class="x">paragraph</EM>.

<<<
<p>Within a <em class="x">paragraph</EM>.</p>
>>> not HTML
Obviously, 3 < 5 and 7 > 2.
Not HTML: <3>, <_a>, <>

<<<
<p>Obviously, 3 &lt; 5 and 7 &gt; 2.
Not HTML: &lt;3&gt;, &lt;_a&gt;, &lt;&gt;</p>
>>> "markdown" within a tag is not parsed
Text <a href="_foo_">And "_foo_"</a>.

<<<
<p>Text <a href="_foo_">And "<em>foo</em>"</a>.</p>