>>> h1
text
===

<<<
<h1>text</h1>
>>> h2
text
---

<<<
<h2>text</h2>
>>> h1 on first line becomes text
===

<<<
<p>===</p>
>>> h2 on first line becomes text
-

<<<
<p>-</p>
>>> h1 turns preceding list into text
- list
===

<<<
<h1>- list</h1>
>>> h2 turns preceding list into text
- list
===

<<<
<h1>- list</h1>
>>> h1 turns preceding blockquote into text
> quote
===

<<<
<h1>> quote</h1>
>>> h2 turns preceding blockquote into text
> quote
===

<<<
<h1>> quote</h1>