diff --git a/README.md b/README.md
index 81ab9c7..b080ced 100644
--- a/README.md
+++ b/README.md
@@ -209,22 +209,26 @@ md = require('markdown-it')('full', {
 
 ## Benchmark
 
-Here is result of CommonMark spec parse at Core i5 2.4 GHz (i5-4258U):
+Here is result of readme parse at MB Pro Retina 2013 (2.4 GHz):
 
 ```bash
-$ benchmark/benchmark.js spec
-Selected samples: (1 of 27)
- > spec
-
-Sample: spec.txt (110610 bytes)
- > commonmark-reference x 68.63 ops/sec ±6.53% (72 runs sampled)
- > current x 79.62 ops/sec ±3.22% (80 runs sampled)
- > current-commonmark x 103 ops/sec ±1.10% (76 runs sampled)
- > marked-0.3.2 x 23.14 ops/sec ±1.66% (42 runs sampled)
+$ benchmark/benchmark.js readme
+Selected samples: (1 of 28)
+ > README
+
+Sample: README.md (7774 bytes)
+ > commonmark-reference x 1,222 ops/sec ±0.96% (97 runs sampled)
+ > current x 743 ops/sec ±0.84% (97 runs sampled)
+ > current-commonmark x 1,568 ops/sec ±0.84% (98 runs sampled)
+ > marked-0.3.2 x 1,587 ops/sec ±4.31% (93 runs sampled)
 ```
 
+__Note.__ CommonMark version runs with [simplified link normalizers](https://github.com/markdown-it/markdown-it/blob/master/benchmark/implementations/current-commonmark/index.js)
+for more "honest" compare. Difference is ~ 1.5x.
+
 As you can see, `markdown-it` doesn't pay with speed for it's flexibility.
-Because it's written in monomorphyc style and uses JIT inline caches effectively.
+Slowdown of "full" version caused by additional features, not available in
+other implementations.
 
 
 ## Authors
diff --git a/benchmark/implementations/current-commonmark/index.js b/benchmark/implementations/current-commonmark/index.js
index feec1dc..0302351 100644
--- a/benchmark/implementations/current-commonmark/index.js
+++ b/benchmark/implementations/current-commonmark/index.js
@@ -2,6 +2,13 @@
 
 var md = require('../../../')('commonmark');
 
+// Replace normalizers to more primitive, for more "honest" compare.
+// Default ones can cause 1.5x slowdown.
+var encode = md.utils.lib.mdurl.encode;
+
+md.normalizeLink     = function(url) { return encode(url); }
+md.normalizeLinkText = function(str) { return str; }
+
 exports.run = function(data) {
   return md.render(data);
 };
diff --git a/benchmark/samples/README.md b/benchmark/samples/README.md
new file mode 100644
index 0000000..81ab9c7
--- /dev/null
+++ b/benchmark/samples/README.md
@@ -0,0 +1,254 @@
+# markdown-it
+
+[![Build Status](https://img.shields.io/travis/markdown-it/markdown-it/master.svg?style=flat)](https://travis-ci.org/markdown-it/markdown-it)
+[![NPM version](https://img.shields.io/npm/v/markdown-it.svg?style=flat)](https://www.npmjs.org/package/markdown-it)
+[![Coverage Status](https://img.shields.io/coveralls/markdown-it/markdown-it/master.svg?style=flat)](https://coveralls.io/r/markdown-it/markdown-it?branch=master)
+[![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/markdown-it/markdown-it)
+
+> Markdown parser done right. Fast and easy to extend.
+
+__[Live demo](https://markdown-it.github.io)__
+
+__v4.+ changed internals! Plugins need update. See [migration details](https://github.com/markdown-it/markdown-it/blob/master/docs/4.0_migration.md)__
+
+- Supports the CommonMark spec + syntax extensions + sugar (URL autolinking, typographer).
+- Configurable syntax! You can add new rules and even replace existing ones.
+- High speed!
+- Community-written __[plugins](https://www.npmjs.org/browse/keyword/markdown-it-plugin)__ and [other packages](https://www.npmjs.org/browse/keyword/markdown-it) on npm.
+
+__Table of content__
+
+- [Install](#install)
+- [Usage examples](#usage-examples)
+- [API](#api)
+- [Syntax extensions](#syntax-extensions)
+- [Benchmark](#benchmark)
+- [Authors](#authors)
+- [References / Thanks](#references--thanks)
+- [License](#license)
+
+## Install
+
+**node.js** & **bower**:
+
+```bash
+npm install markdown-it --save
+bower install markdown-it --save
+```
+
+**browser (CDN):**
+
+- [jsDeliver CDN](http://www.jsdelivr.com/#!markdown-it "jsDelivr CDN")
+- [cdnjs.com CDN](https://cdnjs.com/libraries/markdown-it "cdnjs.com")
+
+
+## Usage examples
+
+See also:
+
+- __[API documentation](https://markdown-it.github.io/markdown-it/)__ - for more
+  info and examples.
+- [Development info](https://github.com/markdown-it/markdown-it/tree/master/docs) -
+  for plugins writers.
+
+
+### Simple
+
+```js
+// node.js, "classic" way:
+var MarkdownIt = require('markdown-it'),
+    md = new MarkdownIt();
+var result = md.render('# markdown-it rulezz!');
+
+// node.js, the same, but with sugar:
+var md = require('markdown-it')();
+var result = md.render('# markdown-it rulezz!');
+
+// browser without AMD, added to "window" on script load
+// Note, there are no dash.
+var md = window.markdownit();
+var result = md.render('# markdown-it rulezz!');
+```
+
+Single line rendering, without paragraph wrap:
+
+```js
+var md = require('markdown-it')();
+var result = md.renderInline('__markdown-it__ rulezz!');
+```
+
+
+### Init with presets and options
+
+(*) preset define combination of active rules and options. Can be
+`"commonmark"`, `"zero"` or `"default"` (if skipped). See
+[API docs](https://markdown-it.github.io/markdown-it/#MarkdownIt.new) for more details.
+
+```js
+// commonmark mode
+var md = require('markdown-it')('commonmark');
+
+// default mode
+var md = require('markdown-it')();
+
+// enable everything
+var md = require('markdown-it')({
+  html: true,
+  linkify: true,
+  typographer: true
+});
+
+// full options list (defaults)
+var md = require('markdown-it')({
+  html:         false,        // Enable HTML tags in source
+  xhtmlOut:     false,        // Use '/' to close single tags (<br />).
+                              // This is only for full CommonMark compatibility.
+  breaks:       false,        // Convert '\n' in paragraphs into <br>
+  langPrefix:   'language-',  // CSS language prefix for fenced blocks. Can be
+                              // useful for external highlighters.
+  linkify:      false,        // Autoconvert URL-like text to links
+
+  // Enable some language-neutral replacement + quotes beautification
+  typographer:  false,
+
+  // Double + single quotes replacement pairs, when typographer enabled,
+  // and smartquotes on. Set doubles to '«»' for Russian, '„“' for German.
+  quotes: '“”‘’',
+
+  // Highlighter function. Should return escaped HTML,
+  // or '' if the source string is not changed and should be escaped externaly.
+  highlight: function (/*str, lang*/) { return ''; }
+});
+```
+
+### Plugins load
+
+```js
+var md = require('markdown-it')()
+            .use(plugin1)
+            .use(plugin2, opts, ...)
+            .use(plugin3);
+```
+
+
+### Syntax highlighting
+
+Apply syntax highlighting to fenced code blocks with the `highlight` option:
+
+```js
+var hljs = require('highlight.js') // https://highlightjs.org/
+
+// Actual default values
+var md = require('markdown-it')({
+  highlight: function (str, lang) {
+    if (lang && hljs.getLanguage(lang)) {
+      try {
+        return hljs.highlight(lang, str).value;
+      } catch (__) {}
+    }
+
+    try {
+      return hljs.highlightAuto(str).value;
+    } catch (__) {}
+
+    return ''; // use external default escaping
+  }
+});
+```
+
+
+## API
+
+__[API documentation](https://markdown-it.github.io/markdown-it/)__
+
+If you are going to write plugins - take a look at
+[Development info](https://github.com/markdown-it/markdown-it/tree/master/docs).
+
+
+## Syntax extensions
+
+Embedded (enabled by default):
+
+- [Tables](https://help.github.com/articles/github-flavored-markdown/#tables) (GFM)
+- [Strikethrough](https://help.github.com/articles/github-flavored-markdown/#strikethrough) (GFM)
+
+Via plugins:
+
+- [subscript](https://github.com/markdown-it/markdown-it-sub)
+- [superscript](https://github.com/markdown-it/markdown-it-sup)
+- [footnote](https://github.com/markdown-it/markdown-it-footnote)
+- [definition list](https://github.com/markdown-it/markdown-it-deflist)
+- [abbreviation](https://github.com/markdown-it/markdown-it-abbr)
+- [emoji](https://github.com/markdown-it/markdown-it-emoji)
+- [custom container](https://github.com/markdown-it/markdown-it-container)
+- [insert](https://github.com/markdown-it/markdown-it-ins)
+- [mark](https://github.com/markdown-it/markdown-it-mark)
+- ... and [others](https://www.npmjs.org/browse/keyword/markdown-it-plugin)
+
+
+### Manage rules
+
+By default all rules are enabled, but can be restricted by options. On plugin
+load all it's rules are enabled automatically.
+
+```js
+// Activate/deactivate rules, with curring
+var md = require('markdown-it')()
+            .disable([ 'link', 'image' ])
+            .enable([ 'link' ])
+            .enable('image');
+
+// Enable everything
+md = require('markdown-it')('full', {
+  html: true,
+  linkify: true,
+  typographer: true,
+});
+```
+
+
+## Benchmark
+
+Here is result of CommonMark spec parse at Core i5 2.4 GHz (i5-4258U):
+
+```bash
+$ benchmark/benchmark.js spec
+Selected samples: (1 of 27)
+ > spec
+
+Sample: spec.txt (110610 bytes)
+ > commonmark-reference x 68.63 ops/sec ±6.53% (72 runs sampled)
+ > current x 79.62 ops/sec ±3.22% (80 runs sampled)
+ > current-commonmark x 103 ops/sec ±1.10% (76 runs sampled)
+ > marked-0.3.2 x 23.14 ops/sec ±1.66% (42 runs sampled)
+```
+
+As you can see, `markdown-it` doesn't pay with speed for it's flexibility.
+Because it's written in monomorphyc style and uses JIT inline caches effectively.
+
+
+## Authors
+
+- Alex Kocharin [github/rlidwka](https://github.com/rlidwka)
+- Vitaly Puzrin [github/puzrin](https://github.com/puzrin)
+
+_markdown-it_ is the result of the decision of the authors who contributed to
+99% of the _Remarkable_ code to move to a project with the same authorship but
+new leadership (Vitaly and Alex). It's not a fork.
+
+## References / Thanks
+
+Big thanks to [John MacFarlane](https://github.com/jgm) for his work on the
+CommonMark spec and reference implementations. His work saved us a lot of time
+during this project's development.
+
+**Related Links:**
+
+- https://github.com/jgm/CommonMark - reference CommonMark implementations in C & JS,
+  also contains latest spec & online demo.
+- http://talk.commonmark.org - CommonMark forum, good place to collaborate
+  developers' efforts.
+
+## License
+
+[MIT](https://github.com/markdown-it/markdown-it/blob/master/LICENSE)
diff --git a/benchmark/samples/spec.txt b/benchmark/samples/spec.txt
deleted file mode 100644
index 0c09c43..0000000
--- a/benchmark/samples/spec.txt
+++ /dev/null
@@ -1,6213 +0,0 @@
----
-title: CommonMark Spec
-author:
-- John MacFarlane
-version: 2
-date: 2014-09-19
-...
-
-# Introduction
-
-## What is Markdown?
-
-Markdown is a plain text format for writing structured documents,
-based on conventions used for indicating formatting in email and
-usenet posts.  It was developed in 2004 by John Gruber, who wrote
-the first Markdown-to-HTML converter in perl, and it soon became
-widely used in websites.  By 2014 there were dozens of
-implementations in many languages.  Some of them extended basic
-Markdown syntax with conventions for footnotes, definition lists,
-tables, and other constructs, and some allowed output not just in
-HTML but in LaTeX and many other formats.
-
-## Why is a spec needed?
-
-John Gruber's [canonical description of Markdown's
-syntax](http://daringfireball.net/projects/markdown/syntax)
-does not specify the syntax unambiguously.  Here are some examples of
-questions it does not answer:
-
-1.  How much indentation is needed for a sublist?  The spec says that
-    continuation paragraphs need to be indented four spaces, but is
-    not fully explicit about sublists.  It is natural to think that
-    they, too, must be indented four spaces, but `Markdown.pl` does
-    not require that.  This is hardly a "corner case," and divergences
-    between implementations on this issue often lead to surprises for
-    users in real documents. (See [this comment by John
-    Gruber](http://article.gmane.org/gmane.text.markdown.general/1997).)
-
-2.  Is a blank line needed before a block quote or header?
-    Most implementations do not require the blank line.  However,
-    this can lead to unexpected results in hard-wrapped text, and
-    also to ambiguities in parsing (note that some implementations
-    put the header inside the blockquote, while others do not).
-    (John Gruber has also spoken [in favor of requiring the blank
-    lines](http://article.gmane.org/gmane.text.markdown.general/2146).)
-
-3.  Is a blank line needed before an indented code block?
-    (`Markdown.pl` requires it, but this is not mentioned in the
-    documentation, and some implementations do not require it.)
-
-    ``` markdown
-    paragraph
-        code?
-    ```
-
-4.  What is the exact rule for determining when list items get
-    wrapped in `<p>` tags?  Can a list be partially "loose" and partially
-    "tight"?  What should we do with a list like this?
-
-    ``` markdown
-    1. one
-
-    2. two
-    3. three
-    ```
-
-    Or this?
-
-    ``` markdown
-    1.  one
-        - a
-
-        - b
-    2.  two
-    ```
-
-    (There are some relevant comments by John Gruber
-    [here](http://article.gmane.org/gmane.text.markdown.general/2554).)
-
-5.  Can list markers be indented?  Can ordered list markers be right-aligned?
-
-    ``` markdown
-     8. item 1
-     9. item 2
-    10. item 2a
-    ```
-
-6.  Is this one list with a horizontal rule in its second item,
-    or two lists separated by a horizontal rule?
-
-    ``` markdown
-    * a
-    * * * * *
-    * b
-    ```
-
-7.  When list markers change from numbers to bullets, do we have
-    two lists or one?  (The Markdown syntax description suggests two,
-    but the perl scripts and many other implementations produce one.)
-
-    ``` markdown
-    1. fee
-    2. fie
-    -  foe
-    -  fum
-    ```
-
-8.  What are the precedence rules for the markers of inline structure?
-    For example, is the following a valid link, or does the code span
-    take precedence ?
-
-    ``` markdown
-    [a backtick (`)](/url) and [another backtick (`)](/url).
-    ```
-
-9.  What are the precedence rules for markers of emphasis and strong
-    emphasis?  For example, how should the following be parsed?
-
-    ``` markdown
-    *foo *bar* baz*
-    ```
-
-10. What are the precedence rules between block-level and inline-level
-    structure?  For example, how should the following be parsed?
-
-    ``` markdown
-    - `a long code span can contain a hyphen like this
-      - and it can screw things up`
-    ```
-
-11. Can list items include headers?  (`Markdown.pl` does not allow this,
-    but headers can occur in blockquotes.)
-
-    ``` markdown
-    - # Heading
-    ```
-
-12. Can link references be defined inside block quotes or list items?
-
-    ``` markdown
-    > Blockquote [foo].
-    >
-    > [foo]: /url
-    ```
-
-13. If there are multiple definitions for the same reference, which takes
-    precedence?
-
-    ``` markdown
-    [foo]: /url1
-    [foo]: /url2
-
-    [foo][]
-    ```
-
-In the absence of a spec, early implementers consulted `Markdown.pl`
-to resolve these ambiguities.  But `Markdown.pl` was quite buggy, and
-gave manifestly bad results in many cases, so it was not a
-satisfactory replacement for a spec.
-
-Because there is no unambiguous spec, implementations have diverged
-considerably.  As a result, users are often surprised to find that
-a document that renders one way on one system (say, a github wiki)
-renders differently on another (say, converting to docbook using
-pandoc).  To make matters worse, because nothing in Markdown counts
-as a "syntax error," the divergence often isn't discovered right away.
-
-## About this document
-
-This document attempts to specify Markdown syntax unambiguously.
-It contains many examples with side-by-side Markdown and
-HTML.  These are intended to double as conformance tests.  An
-accompanying script `runtests.pl` can be used to run the tests
-against any Markdown program:
-
-    perl runtests.pl spec.txt PROGRAM
-
-Since this document describes how Markdown is to be parsed into
-an abstract syntax tree, it would have made sense to use an abstract
-representation of the syntax tree instead of HTML.  But HTML is capable
-of representing the structural distinctions we need to make, and the
-choice of HTML for the tests makes it possible to run the tests against
-an implementation without writing an abstract syntax tree renderer.
-
-This document is generated from a text file, `spec.txt`, written
-in Markdown with a small extension for the side-by-side tests.
-The script `spec2md.pl` can be used to turn `spec.txt` into pandoc
-Markdown, which can then be converted into other formats.
-
-In the examples, the `→` character is used to represent tabs.
-
-# Preprocessing
-
-A [line](#line) <a id="line"></a>
-is a sequence of zero or more characters followed by a line
-ending (CR, LF, or CRLF) or by the end of
-file.
-
-This spec does not specify an encoding; it thinks of lines as composed
-of characters rather than bytes.  A conforming parser may be limited
-to a certain encoding.
-
-Tabs in lines are expanded to spaces, with a tab stop of 4 characters:
-
-.
-→foo→baz→→bim
-.
-<pre><code>foo baz     bim
-</code></pre>
-.
-
-.
-    a→a
-    ὐ→a
-.
-<pre><code>a   a
-ὐ   a
-</code></pre>
-.
-
-Line endings are replaced by newline characters (LF).
-
-A line containing no characters, or a line containing only spaces (after
-tab expansion), is called a [blank line](#blank-line).
-<a id="blank-line"></a>
-
-# Blocks and inlines
-
-We can think of a document as a sequence of [blocks](#block)<a
-id="block"></a>---structural elements like paragraphs, block quotations,
-lists, headers, rules, and code blocks.  Blocks can contain other
-blocks, or they can contain [inline](#inline)<a id="inline"></a> content:
-words, spaces, links, emphasized text, images, and inline code.
-
-## Precedence
-
-Indicators of block structure always take precedence over indicators
-of inline structure.  So, for example, the following is a list with
-two items, not a list with one item containing a code span:
-
-.
-- `one
-- two`
-.
-<ul>
-<li>`one</li>
-<li>two`</li>
-</ul>
-.
-
-This means that parsing can proceed in two steps:  first, the block
-structure of the document can be discerned; second, text lines inside
-paragraphs, headers, and other block constructs can be parsed for inline
-structure.  The second step requires information about link reference
-definitions that will be available only at the end of the first
-step.  Note that the first step requires processing lines in sequence,
-but the second can be parallelized, since the inline parsing of
-one block element does not affect the inline parsing of any other.
-
-## Container blocks and leaf blocks
-
-We can divide blocks into two types:
-[container blocks](#container-block), <a id="container-block"></a>
-which can contain other blocks, and [leaf blocks](#leaf-block),
-<a id="leaf-block"></a> which cannot.
-
-# Leaf blocks
-
-This section describes the different kinds of leaf block that make up a
-Markdown document.
-
-## Horizontal rules
-
-A line consisting of 0-3 spaces of indentation, followed by a sequence
-of three or more matching `-`, `_`, or `*` characters, each followed
-optionally by any number of spaces, forms a [horizontal
-rule](#horizontal-rule). <a id="horizontal-rule"></a>
-
-.
-***
----
-___
-.
-<hr />
-<hr />
-<hr />
-.
-
-Wrong characters:
-
-.
-+++
-.
-<p>+++</p>
-.
-
-.
-===
-.
-<p>===</p>
-.
-
-Not enough characters:
-
-.
---
-**
-__
-.
-<p>--
-**
-__</p>
-.
-
-One to three spaces indent are allowed:
-
-.
- ***
-  ***
-   ***
-.
-<hr />
-<hr />
-<hr />
-.
-
-Four spaces is too many:
-
-.
-    ***
-.
-<pre><code>***
-</code></pre>
-.
-
-.
-Foo
-    ***
-.
-<p>Foo
-***</p>
-.
-
-More than three characters may be used:
-
-.
-_____________________________________
-.
-<hr />
-.
-
-Spaces are allowed between the characters:
-
-.
- - - -
-.
-<hr />
-.
-
-.
- **  * ** * ** * **
-.
-<hr />
-.
-
-.
--     -      -      -
-.
-<hr />
-.
-
-Spaces are allowed at the end:
-
-.
-- - - -    
-.
-<hr />
-.
-
-However, no other characters may occur at the end or the
-beginning:
-
-.
-_ _ _ _ a
-
-a------
-.
-<p>_ _ _ _ a</p>
-<p>a------</p>
-.
-
-It is required that all of the non-space characters be the same.
-So, this is not a horizontal rule:
-
-.
- *-*
-.
-<p><em>-</em></p>
-.
-
-Horizontal rules do not need blank lines before or after:
-
-.
-- foo
-***
-- bar
-.
-<ul>
-<li>foo</li>
-</ul>
-<hr />
-<ul>
-<li>bar</li>
-</ul>
-.
-
-Horizontal rules can interrupt a paragraph:
-
-.
-Foo
-***
-bar
-.
-<p>Foo</p>
-<hr />
-<p>bar</p>
-.
-
-Note, however, that this is a setext header, not a paragraph followed
-by a horizontal rule:
-
-.
-Foo
----
-bar
-.
-<h2>Foo</h2>
-<p>bar</p>
-.
-
-When both a horizontal rule and a list item are possible
-interpretations of a line, the horizontal rule is preferred:
-
-.
-* Foo
-* * *
-* Bar
-.
-<ul>
-<li>Foo</li>
-</ul>
-<hr />
-<ul>
-<li>Bar</li>
-</ul>
-.
-
-If you want a horizontal rule in a list item, use a different bullet:
-
-.
-- Foo
-- * * *
-.
-<ul>
-<li>Foo</li>
-<li><hr /></li>
-</ul>
-.
-
-## ATX headers
-
-An [ATX header](#atx-header) <a id="atx-header"></a>
-consists of a string of characters, parsed as inline content, between an
-opening sequence of 1--6 unescaped `#` characters and an optional
-closing sequence of any number of `#` characters.  The opening sequence
-of `#` characters cannot be followed directly by a nonspace character.
-The closing `#` characters may be followed by spaces only.  The opening
-`#` character may be indented 0-3 spaces.  The raw contents of the
-header are stripped of leading and trailing spaces before being parsed
-as inline content.  The header level is equal to the number of `#`
-characters in the opening sequence.
-
-Simple headers:
-
-.
-# foo
-## foo
-### foo
-#### foo
-##### foo
-###### foo
-.
-<h1>foo</h1>
-<h2>foo</h2>
-<h3>foo</h3>
-<h4>foo</h4>
-<h5>foo</h5>
-<h6>foo</h6>
-.
-
-More than six `#` characters is not a header:
-
-.
-####### foo
-.
-<p>####### foo</p>
-.
-
-A space is required between the `#` characters and the header's
-contents.  Note that many implementations currently do not require
-the space.  However, the space was required by the [original ATX
-implementation](http://www.aaronsw.com/2002/atx/atx.py), and it helps
-prevent things like the following from being parsed as headers:
-
-.
-#5 bolt
-.
-<p>#5 bolt</p>
-.
-
-This is not a header, because the first `#` is escaped:
-
-.
-\## foo
-.
-<p>## foo</p>
-.
-
-Contents are parsed as inlines:
-
-.
-# foo *bar* \*baz\*
-.
-<h1>foo <em>bar</em> *baz*</h1>
-.
-
-Leading and trailing blanks are ignored in parsing inline content:
-
-.
-#                  foo                     
-.
-<h1>foo</h1>
-.
-
-One to three spaces indentation are allowed:
-
-.
- ### foo
-  ## foo
-   # foo
-.
-<h3>foo</h3>
-<h2>foo</h2>
-<h1>foo</h1>
-.
-
-Four spaces are too much:
-
-.
-    # foo
-.
-<pre><code># foo
-</code></pre>
-.
-
-.
-foo
-    # bar
-.
-<p>foo
-# bar</p>
-.
-
-A closing sequence of `#` characters is optional:
-
-.
-## foo ##
-  ###   bar    ###
-.
-<h2>foo</h2>
-<h3>bar</h3>
-.
-
-It need not be the same length as the opening sequence:
-
-.
-# foo ##################################
-##### foo ##
-.
-<h1>foo</h1>
-<h5>foo</h5>
-.
-
-Spaces are allowed after the closing sequence:
-
-.
-### foo ###     
-.
-<h3>foo</h3>
-.
-
-A sequence of `#` characters with a nonspace character following it
-is not a closing sequence, but counts as part of the contents of the
-header:
-
-.
-### foo ### b
-.
-<h3>foo ### b</h3>
-.
-
-Backslash-escaped `#` characters do not count as part
-of the closing sequence:
-
-.
-### foo \###
-## foo \#\##
-# foo \#
-.
-<h3>foo #</h3>
-<h2>foo ##</h2>
-<h1>foo #</h1>
-.
-
-ATX headers need not be separated from surrounding content by blank
-lines, and they can interrupt paragraphs:
-
-.
-****
-## foo
-****
-.
-<hr />
-<h2>foo</h2>
-<hr />
-.
-
-.
-Foo bar
-# baz
-Bar foo
-.
-<p>Foo bar</p>
-<h1>baz</h1>
-<p>Bar foo</p>
-.
-
-ATX headers can be empty:
-
-.
-## 
-#
-### ###
-.
-<h2></h2>
-<h1></h1>
-<h3></h3>
-.
-
-## Setext headers
-
-A [setext header](#setext-header) <a id="setext-header"></a>
-consists of a line of text, containing at least one nonspace character,
-with no more than 3 spaces indentation, followed by a [setext header
-underline](#setext-header-underline).  A [setext header
-underline](#setext-header-underline) <a id="setext-header-underline"></a>
-is a sequence of `=` characters or a sequence of `-` characters, with no
-more than 3 spaces indentation and any number of trailing
-spaces.  The header is a level 1 header if `=` characters are used, and
-a level 2 header if `-` characters are used.  The contents of the header
-are the result of parsing the first line as Markdown inline content.
-
-In general, a setext header need not be preceded or followed by a
-blank line.  However, it cannot interrupt a paragraph, so when a
-setext header comes after a paragraph, a blank line is needed between
-them.
-
-Simple examples:
-
-.
-Foo *bar*
-=========
-
-Foo *bar*
----------
-.
-<h1>Foo <em>bar</em></h1>
-<h2>Foo <em>bar</em></h2>
-.
-
-The underlining can be any length:
-
-.
-Foo
--------------------------
-
-Foo
-=
-.
-<h2>Foo</h2>
-<h1>Foo</h1>
-.
-
-The header content can be indented up to three spaces, and need
-not line up with the underlining:
-
-.
-   Foo
----
-
-  Foo
------
-
-  Foo
-  ===
-.
-<h2>Foo</h2>
-<h2>Foo</h2>
-<h1>Foo</h1>
-.
-
-Four spaces indent is too much:
-
-.
-    Foo
-    ---
-
-    Foo
----
-.
-<pre><code>Foo
----
-
-Foo
-</code></pre>
-<hr />
-.
-
-The setext header underline can be indented up to three spaces, and
-may have trailing spaces:
-
-.
-Foo
-   ----      
-.
-<h2>Foo</h2>
-.
-
-Four spaces is too much:
-
-.
-Foo
-     ---
-.
-<p>Foo
----</p>
-.
-
-The setext header underline cannot contain internal spaces:
-
-.
-Foo
-= =
-
-Foo
---- -
-.
-<p>Foo
-= =</p>
-<p>Foo</p>
-<hr />
-.
-
-Trailing spaces in the content line do not cause a line break:
-
-.
-Foo  
------
-.
-<h2>Foo</h2>
-.
-
-Nor does a backslash at the end:
-
-.
-Foo\
-----
-.
-<h2>Foo\</h2>
-.
-
-Since indicators of block structure take precedence over
-indicators of inline structure, the following are setext headers:
-
-.
-`Foo
-----
-`
-
-<a title="a lot
----
-of dashes"/>
-.
-<h2>`Foo</h2>
-<p>`</p>
-<h2>&lt;a title=&quot;a lot</h2>
-<p>of dashes&quot;/&gt;</p>
-.
-
-The setext header underline cannot be a lazy line:
-
-.
-> Foo
----
-.
-<blockquote>
-<p>Foo</p>
-</blockquote>
-<hr />
-.
-
-A setext header cannot interrupt a paragraph:
-
-.
-Foo
-Bar
----
-
-Foo
-Bar
-===
-.
-<p>Foo
-Bar</p>
-<hr />
-<p>Foo
-Bar
-===</p>
-.
-
-But in general a blank line is not required before or after:
-
-.
----
-Foo
----
-Bar
----
-Baz
-.
-<hr />
-<h2>Foo</h2>
-<h2>Bar</h2>
-<p>Baz</p>
-.
-
-Setext headers cannot be empty:
-
-.
-
-====
-.
-<p>====</p>
-.
-
-
-## Indented code blocks
-
-An [indented code block](#indented-code-block)
-<a id="indented-code-block"></a> is composed of one or more
-[indented chunks](#indented-chunk) separated by blank lines.
-An [indented chunk](#indented-chunk) <a id="indented-chunk"></a>
-is a sequence of non-blank lines, each indented four or more
-spaces.  An indented code block cannot interrupt a paragraph, so
-if it occurs before or after a paragraph, there must be an
-intervening blank line.  The contents of the code block are
-the literal contents of the lines, including trailing newlines,
-minus four spaces of indentation. An indented code block has no
-attributes.
-
-.
-    a simple
-      indented code block
-.
-<pre><code>a simple
-  indented code block
-</code></pre>
-.
-
-The contents are literal text, and do not get parsed as Markdown:
-
-.
-    <a/>
-    *hi*
-
-    - one
-.
-<pre><code>&lt;a/&gt;
-*hi*
-
-- one
-</code></pre>
-.
-
-Here we have three chunks separated by blank lines:
-
-.
-    chunk1
-
-    chunk2
-  
- 
- 
-    chunk3
-.
-<pre><code>chunk1
-
-chunk2
-
-
-
-chunk3
-</code></pre>
-.
-
-Any initial spaces beyond four will be included in the content, even
-in interior blank lines:
-
-.
-    chunk1
-      
-      chunk2
-.
-<pre><code>chunk1
-  
-  chunk2
-</code></pre>
-.
-
-An indented code block cannot interrupt a paragraph.  (This
-allows hanging indents and the like.)
-
-.
-Foo
-    bar
-
-.
-<p>Foo
-bar</p>
-.
-
-However, any non-blank line with fewer than four leading spaces ends
-the code block immediately.  So a paragraph may occur immediately
-after indented code:
-
-.
-    foo
-bar
-.
-<pre><code>foo
-</code></pre>
-<p>bar</p>
-.
-
-And indented code can occur immediately before and after other kinds of
-blocks:
-
-.
-# Header
-    foo
-Header
-------
-    foo
-----
-.
-<h1>Header</h1>
-<pre><code>foo
-</code></pre>
-<h2>Header</h2>
-<pre><code>foo
-</code></pre>
-<hr />
-.
-
-The first line can be indented more than four spaces:
-
-.
-        foo
-    bar
-.
-<pre><code>    foo
-bar
-</code></pre>
-.
-
-Blank lines preceding or following an indented code block
-are not included in it:
-
-.
-
-    
-    foo
-    
-
-.
-<pre><code>foo
-</code></pre>
-.
-
-Trailing spaces are included in the code block's content:
-
-.
-    foo  
-.
-<pre><code>foo  
-</code></pre>
-.
-
-
-## Fenced code blocks
-
-A [code fence](#code-fence) <a id="code-fence"></a> is a sequence
-of at least three consecutive backtick characters (`` ` ``) or
-tildes (`~`).  (Tildes and backticks cannot be mixed.)
-A [fenced code block](#fenced-code-block) <a id="fenced-code-block"></a>
-begins with a code fence, indented no more than three spaces.
-
-The line with the opening code fence may optionally contain some text
-following the code fence; this is trimmed of leading and trailing
-spaces and called the [info string](#info-string).
-<a id="info-string"></a> The info string may not contain any backtick
-characters.  (The reason for this restriction is that otherwise
-some inline code would be incorrectly interpreted as the
-beginning of a fenced code block.)
-
-The content of the code block consists of all subsequent lines, until
-a closing [code fence](#code-fence) of the same type as the code block
-began with (backticks or tildes), and with at least as many backticks
-or tildes as the opening code fence.  If the leading code fence is
-indented N spaces, then up to N spaces of indentation are removed from
-each line of the content (if present).  (If a content line is not
-indented, it is preserved unchanged.  If it is indented less than N
-spaces, all of the indentation is removed.)
-
-The closing code fence may be indented up to three spaces, and may be
-followed only by spaces, which are ignored.  If the end of the
-containing block (or document) is reached and no closing code fence
-has been found, the code block contains all of the lines after the
-opening code fence until the end of the containing block (or
-document).  (An alternative spec would require backtracking in the
-event that a closing code fence is not found.  But this makes parsing
-much less efficient, and there seems to be no real down side to the
-behavior described here.)
-
-A fenced code block may interrupt a paragraph, and does not require
-a blank line either before or after.
-
-The content of a code fence is treated as literal text, not parsed
-as inlines.  The first word of the info string is typically used to
-specify the language of the code sample, and rendered in the `class`
-attribute of the `code` tag.  However, this spec does not mandate any
-particular treatment of the info string.
-
-Here is a simple example with backticks:
-
-.
-```
-<
- >
-```
-.
-<pre><code>&lt;
- &gt;
-</code></pre>
-.
-
-With tildes:
-
-.
-~~~
-<
- >
-~~~
-.
-<pre><code>&lt;
- &gt;
-</code></pre>
-.
-
-The closing code fence must use the same character as the opening
-fence:
-
-.
-```
-aaa
-~~~
-```
-.
-<pre><code>aaa
-~~~
-</code></pre>
-.
-
-.
-~~~
-aaa
-```
-~~~
-.
-<pre><code>aaa
-```
-</code></pre>
-.
-
-The closing code fence must be at least as long as the opening fence:
-
-.
-````
-aaa
-```
-``````
-.
-<pre><code>aaa
-```
-</code></pre>
-.
-
-.
-~~~~
-aaa
-~~~
-~~~~
-.
-<pre><code>aaa
-~~~
-</code></pre>
-.
-
-Unclosed code blocks are closed by the end of the document:
-
-.
-```
-.
-<pre><code></code></pre>
-.
-
-.
-`````
-
-```
-aaa
-.
-<pre><code>
-```
-aaa
-</code></pre>
-.
-
-A code block can have all empty lines as its content:
-
-.
-```
-
-  
-```
-.
-<pre><code>
-  
-</code></pre>
-.
-
-A code block can be empty:
-
-.
-```
-```
-.
-<pre><code></code></pre>
-.
-
-Fences can be indented.  If the opening fence is indented,
-content lines will have equivalent opening indentation removed,
-if present:
-
-.
- ```
- aaa
-aaa
-```
-.
-<pre><code>aaa
-aaa
-</code></pre>
-.
-
-.
-  ```
-aaa
-  aaa
-aaa
-  ```
-.
-<pre><code>aaa
-aaa
-aaa
-</code></pre>
-.
-
-.
-   ```
-   aaa
-    aaa
-  aaa
-   ```
-.
-<pre><code>aaa
- aaa
-aaa
-</code></pre>
-.
-
-Four spaces indentation produces an indented code block:
-
-.
-    ```
-    aaa
-    ```
-.
-<pre><code>```
-aaa
-```
-</code></pre>
-.
-
-Code fences (opening and closing) cannot contain internal spaces:
-
-.
-``` ```
-aaa
-.
-<p><code></code>
-aaa</p>
-.
-
-.
-~~~~~~
-aaa
-~~~ ~~
-.
-<pre><code>aaa
-~~~ ~~
-</code></pre>
-.
-
-Fenced code blocks can interrupt paragraphs, and can be followed
-directly by paragraphs, without a blank line between:
-
-.
-foo
-```
-bar
-```
-baz
-.
-<p>foo</p>
-<pre><code>bar
-</code></pre>
-<p>baz</p>
-.
-
-Other blocks can also occur before and after fenced code blocks
-without an intervening blank line:
-
-.
-foo
----
-~~~
-bar
-~~~
-# baz
-.
-<h2>foo</h2>
-<pre><code>bar
-</code></pre>
-<h1>baz</h1>
-.
-
-An [info string](#info-string) can be provided after the opening code fence.
-Opening and closing spaces will be stripped, and the first word, prefixed
-with `language-`, is used as the value for the `class` attribute of the
-`code` element within the enclosing `pre` element.
-
-.
-```ruby
-def foo(x)
-  return 3
-end
-```
-.
-<pre><code class="language-ruby">def foo(x)
-  return 3
-end
-</code></pre>
-.
-
-.
-~~~~    ruby startline=3 $%@#$
-def foo(x)
-  return 3
-end
-~~~~~~~
-.
-<pre><code class="language-ruby">def foo(x)
-  return 3
-end
-</code></pre>
-.
-
-.
-````;
-````
-.
-<pre><code class="language-;"></code></pre>
-.
-
-Info strings for backtick code blocks cannot contain backticks:
-
-.
-``` aa ```
-foo
-.
-<p><code>aa</code>
-foo</p>
-.
-
-Closing code fences cannot have info strings:
-
-.
-```
-``` aaa
-```
-.
-<pre><code>``` aaa
-</code></pre>
-.
-
-
-## HTML blocks
-
-An [HTML block tag](#html-block-tag) <a id="html-block-tag"></a> is
-an [open tag](#open-tag) or [closing tag](#closing-tag) whose tag
-name is one of the following (case-insensitive):
-`article`, `header`, `aside`, `hgroup`, `blockquote`, `hr`, `iframe`,
-`body`, `li`, `map`, `button`, `object`, `canvas`, `ol`, `caption`,
-`output`, `col`, `p`, `colgroup`, `pre`, `dd`, `progress`, `div`,
-`section`, `dl`, `table`, `td`, `dt`, `tbody`, `embed`, `textarea`,
-`fieldset`, `tfoot`, `figcaption`, `th`, `figure`, `thead`, `footer`,
-`tr`, `form`, `ul`, `h1`, `h2`, `h3`, `h4`, `h5`, `h6`, `video`,
-`script`, `style`.
-
-An [HTML block](#html-block) <a id="html-block"></a> begins with an
-[HTML block tag](#html-block-tag), [HTML comment](#html-comment),
-[processing instruction](#processing-instruction),
-[declaration](#declaration), or [CDATA section](#cdata-section).
-It ends when a [blank line](#blank-line) or the end of the
-input is encountered.  The initial line may be indented up to three
-spaces, and subsequent lines may have any indentation.  The contents
-of the HTML block are interpreted as raw HTML, and will not be escaped
-in HTML output.
-
-Some simple examples:
-
-.
-<table>
-  <tr>
-    <td>
-           hi
-    </td>
-  </tr>
-</table>
-
-okay.
-.
-<table>
-  <tr>
-    <td>
-           hi
-    </td>
-  </tr>
-</table>
-<p>okay.</p>
-.
-
-.
- <div>
-  *hello*
-         <foo><a>
-.
- <div>
-  *hello*
-         <foo><a>
-.
-
-Here we have two code blocks with a Markdown paragraph between them:
-
-.
-<DIV CLASS="foo">
-
-*Markdown*
-
-</DIV>
-.
-<DIV CLASS="foo">
-<p><em>Markdown</em></p>
-</DIV>
-.
-
-In the following example, what looks like a Markdown code block
-is actually part of the HTML block, which continues until a blank
-line or the end of the document is reached:
-
-.
-<div></div>
-``` c
-int x = 33;
-```
-.
-<div></div>
-``` c
-int x = 33;
-```
-.
-
-A comment:
-
-.
-<!-- Foo
-bar
-   baz -->
-.
-<!-- Foo
-bar
-   baz -->
-.
-
-A processing instruction:
-
-.
-<?php
-  echo 'foo'
-?>
-.
-<?php
-  echo 'foo'
-?>
-.
-
-CDATA:
-
-.
-<![CDATA[
-function matchwo(a,b)
-{
-if (a < b && a < 0) then
-  {
-  return 1;
-  }
-else
-  {
-  return 0;
-  }
-}
-]]>
-.
-<![CDATA[
-function matchwo(a,b)
-{
-if (a < b && a < 0) then
-  {
-  return 1;
-  }
-else
-  {
-  return 0;
-  }
-}
-]]>
-.
-
-The opening tag can be indented 1-3 spaces, but not 4:
-
-.
-  <!-- foo -->
-
-    <!-- foo -->
-.
-  <!-- foo -->
-<pre><code>&lt;!-- foo --&gt;
-</code></pre>
-.
-
-An HTML block can interrupt a paragraph, and need not be preceded
-by a blank line.
-
-.
-Foo
-<div>
-bar
-</div>
-.
-<p>Foo</p>
-<div>
-bar
-</div>
-.
-
-However, a following blank line is always needed, except at the end of
-a document:
-
-.
-<div>
-bar
-</div>
-*foo*
-.
-<div>
-bar
-</div>
-*foo*
-.
-
-An incomplete HTML block tag may also start an HTML block:
-
-.
-<div class
-foo
-.
-<div class
-foo
-.
-
-This rule differs from John Gruber's original Markdown syntax
-specification, which says:
-
-> The only restrictions are that block-level HTML elements —
-> e.g. `<div>`, `<table>`, `<pre>`, `<p>`, etc. — must be separated from
-> surrounding content by blank lines, and the start and end tags of the
-> block should not be indented with tabs or spaces.
-
-In some ways Gruber's rule is more restrictive than the one given
-here:
-
-- It requires that an HTML block be preceded by a blank line.
-- It does not allow the start tag to be indented.
-- It requires a matching end tag, which it also does not allow to
-  be indented.
-
-Indeed, most Markdown implementations, including some of Gruber's
-own perl implementations, do not impose these restrictions.
-
-There is one respect, however, in which Gruber's rule is more liberal
-than the one given here, since it allows blank lines to occur inside
-an HTML block.  There are two reasons for disallowing them here.
-First, it removes the need to parse balanced tags, which is
-expensive and can require backtracking from the end of the document
-if no matching end tag is found. Second, it provides a very simple
-and flexible way of including Markdown content inside HTML tags:
-simply separate the Markdown from the HTML using blank lines:
-
-.
-<div>
-
-*Emphasized* text.
-
-</div>
-.
-<div>
-<p><em>Emphasized</em> text.</p>
-</div>
-.
-
-Compare:
-
-.
-<div>
-*Emphasized* text.
-</div>
-.
-<div>
-*Emphasized* text.
-</div>
-.
-
-Some Markdown implementations have adopted a convention of
-interpreting content inside tags as text if the open tag has
-the attribute `markdown=1`.  The rule given above seems a simpler and
-more elegant way of achieving the same expressive power, which is also
-much simpler to parse.
-
-The main potential drawback is that one can no longer paste HTML
-blocks into Markdown documents with 100% reliability.  However,
-*in most cases* this will work fine, because the blank lines in
-HTML are usually followed by HTML block tags.  For example:
-
-.
-<table>
-
-<tr>
-
-<td>
-Hi
-</td>
-
-</tr>
-
-</table>
-.
-<table>
-<tr>
-<td>
-Hi
-</td>
-</tr>
-</table>
-.
-
-Moreover, blank lines are usually not necessary and can be
-deleted.  The exception is inside `<pre>` tags; here, one can
-replace the blank lines with `&#10;` entities.
-
-So there is no important loss of expressive power with the new rule.
-
-## Link reference definitions
-
-A [link reference definition](#link-reference-definition)
-<a id="link-reference-definition"></a> consists of a [link
-label](#link-label), indented up to three spaces, followed
-by a colon (`:`), optional blank space (including up to one
-newline), a [link destination](#link-destination), optional
-blank space (including up to one newline), and an optional [link
-title](#link-title), which if it is present must be separated
-from the [link destination](#link-destination) by whitespace.
-No further non-space characters may occur on the line.
-
-A [link reference-definition](#link-reference-definition)
-does not correspond to a structural element of a document.  Instead, it
-defines a label which can be used in [reference links](#reference-link)
-and reference-style [images](#image) elsewhere in the document.  [Link
-reference definitions] can come either before or after the links that use
-them.
-
-.
-[foo]: /url "title"
-
-[foo]
-.
-<p><a href="/url" title="title">foo</a></p>
-.
-
-.
-   [foo]: 
-      /url  
-           'the title'  
-
-[foo]
-.
-<p><a href="/url" title="the title">foo</a></p>
-.
-
-.
-[Foo*bar\]]:my_(url) 'title (with parens)'
-
-[Foo*bar\]]
-.
-<p><a href="my_(url)" title="title (with parens)">Foo*bar]</a></p>
-.
-
-.
-[Foo bar]:
-<my url>
-'title'
-
-[Foo bar]
-.
-<p><a href="my%20url" title="title">Foo bar</a></p>
-.
-
-The title may be omitted:
-
-.
-[foo]:
-/url
-
-[foo]
-.
-<p><a href="/url">foo</a></p>
-.
-
-The link destination may not be omitted:
-
-.
-[foo]:
-
-[foo]
-.
-<p>[foo]:</p>
-<p>[foo]</p>
-.
-
-A link can come before its corresponding definition:
-
-.
-[foo]
-
-[foo]: url
-.
-<p><a href="url">foo</a></p>
-.
-
-If there are several matching definitions, the first one takes
-precedence:
-
-.
-[foo]
-
-[foo]: first
-[foo]: second
-.
-<p><a href="first">foo</a></p>
-.
-
-As noted in the section on [Links], matching of labels is
-case-insensitive (see [matches](#matches)).
-
-.
-[FOO]: /url
-
-[Foo]
-.
-<p><a href="/url">Foo</a></p>
-.
-
-.
-[ΑΓΩ]: /φου
-
-[αγω]
-.
-<p><a href="/%CF%86%CE%BF%CF%85">αγω</a></p>
-.
-
-Here is a link reference definition with no corresponding link.
-It contributes nothing to the document.
-
-.
-[foo]: /url
-.
-.
-
-This is not a link reference definition, because there are
-non-space characters after the title:
-
-.
-[foo]: /url "title" ok
-.
-<p>[foo]: /url &quot;title&quot; ok</p>
-.
-
-This is not a link reference definition, because it is indented
-four spaces:
-
-.
-    [foo]: /url "title"
-
-[foo]
-.
-<pre><code>[foo]: /url &quot;title&quot;
-</code></pre>
-<p>[foo]</p>
-.
-
-This is not a link reference definition, because it occurs inside
-a code block:
-
-.
-```
-[foo]: /url
-```
-
-[foo]
-.
-<pre><code>[foo]: /url
-</code></pre>
-<p>[foo]</p>
-.
-
-A [link reference definition](#link-reference-definition) cannot
-interrupt a paragraph.
-
-.
-Foo
-[bar]: /baz
-
-[bar]
-.
-<p>Foo
-[bar]: /baz</p>
-<p>[bar]</p>
-.
-
-However, it can directly follow other block elements, such as headers
-and horizontal rules, and it need not be followed by a blank line.
-
-.
-# [Foo]
-[foo]: /url
-> bar
-.
-<h1><a href="/url">Foo</a></h1>
-<blockquote>
-<p>bar</p>
-</blockquote>
-.
-
-Several [link references](#link-reference) can occur one after another,
-without intervening blank lines.
-
-.
-[foo]: /foo-url "foo"
-[bar]: /bar-url
-  "bar"
-[baz]: /baz-url
-
-[foo],
-[bar],
-[baz]
-.
-<p><a href="/foo-url" title="foo">foo</a>,
-<a href="/bar-url" title="bar">bar</a>,
-<a href="/baz-url">baz</a></p>
-.
-
-[Link reference definitions](#link-reference-definition) can occur
-inside block containers, like lists and block quotations.  They
-affect the entire document, not just the container in which they
-are defined:
-
-.
-[foo]
-
-> [foo]: /url
-.
-<p><a href="/url">foo</a></p>
-<blockquote>
-</blockquote>
-.
-
-
-## Paragraphs
-
-A sequence of non-blank lines that cannot be interpreted as other
-kinds of blocks forms a [paragraph](#paragraph).<a id="paragraph"></a>
-The contents of the paragraph are the result of parsing the
-paragraph's raw content as inlines.  The paragraph's raw content
-is formed by concatenating the lines and removing initial and final
-spaces.
-
-A simple example with two paragraphs:
-
-.
-aaa
-
-bbb
-.
-<p>aaa</p>
-<p>bbb</p>
-.
-
-Paragraphs can contain multiple lines, but no blank lines:
-
-.
-aaa
-bbb
-
-ccc
-ddd
-.
-<p>aaa
-bbb</p>
-<p>ccc
-ddd</p>
-.
-
-Multiple blank lines between paragraph have no effect:
-
-.
-aaa
-
-
-bbb
-.
-<p>aaa</p>
-<p>bbb</p>
-.
-
-Leading spaces are skipped:
-
-.
-  aaa
- bbb
-.
-<p>aaa
-bbb</p>
-.
-
-Lines after the first may be indented any amount, since indented
-code blocks cannot interrupt paragraphs.
-
-.
-aaa
-             bbb
-                                       ccc
-.
-<p>aaa
-bbb
-ccc</p>
-.
-
-However, the first line may be indented at most three spaces,
-or an indented code block will be triggered:
-
-.
-   aaa
-bbb
-.
-<p>aaa
-bbb</p>
-.
-
-.
-    aaa
-bbb
-.
-<pre><code>aaa
-</code></pre>
-<p>bbb</p>
-.
-
-Final spaces are stripped before inline parsing, so a paragraph
-that ends with two or more spaces will not end with a hard line
-break:
-
-.
-aaa     
-bbb     
-.
-<p>aaa<br />
-bbb</p>
-.
-
-## Blank lines
-
-[Blank lines](#blank-line) between block-level elements are ignored,
-except for the role they play in determining whether a [list](#list)
-is [tight](#tight) or [loose](#loose).
-
-Blank lines at the beginning and end of the document are also ignored.
-
-.
-  
-
-aaa
-  
-
-# aaa
-
-  
-.
-<p>aaa</p>
-<h1>aaa</h1>
-.
-
-
-# Container blocks
-
-A [container block](#container-block) is a block that has other
-blocks as its contents.  There are two basic kinds of container blocks:
-[block quotes](#block-quote) and [list items](#list-item).
-[Lists](#list) are meta-containers for [list items](#list-item).
-
-We define the syntax for container blocks recursively.  The general
-form of the definition is:
-
-> If X is a sequence of blocks, then the result of
-> transforming X in such-and-such a way is a container of type Y
-> with these blocks as its content.
-
-So, we explain what counts as a block quote or list item by explaining
-how these can be *generated* from their contents. This should suffice
-to define the syntax, although it does not give a recipe for *parsing*
-these constructions.  (A recipe is provided below in the section entitled
-[A parsing strategy](#appendix-a-a-parsing-strategy).)
-
-## Block quotes
-
-A [block quote marker](#block-quote-marker) <a id="block-quote-marker"></a>
-consists of 0-3 spaces of initial indent, plus (a) the character `>` together
-with a following space, or (b) a single character `>` not followed by a space.
-
-The following rules define [block quotes](#block-quote):
-<a id="block-quote"></a>
-
-1.  **Basic case.**  If a string of lines *Ls* constitute a sequence
-    of blocks *Bs*, then the result of prepending a [block quote
-    marker](#block-quote-marker) to the beginning of each line in *Ls*
-    is a [block quote](#block-quote) containing *Bs*.
-
-2.  **Laziness.**  If a string of lines *Ls* constitute a [block
-    quote](#block-quote) with contents *Bs*, then the result of deleting
-    the initial [block quote marker](#block-quote-marker) from one or
-    more lines in which the next non-space character after the [block
-    quote marker](#block-quote-marker) is [paragraph continuation
-    text](#paragraph-continuation-text) is a block quote with *Bs* as
-    its content.  <a id="paragraph-continuation-text"></a>
-    [Paragraph continuation text](#paragraph-continuation-text) is text
-    that will be parsed as part of the content of a paragraph, but does
-    not occur at the beginning of the paragraph.
-
-3.  **Consecutiveness.**  A document cannot contain two [block
-    quotes](#block-quote) in a row unless there is a [blank
-    line](#blank-line) between them.
-
-Nothing else counts as a [block quote](#block-quote).
-
-Here is a simple example:
-
-.
-> # Foo
-> bar
-> baz
-.
-<blockquote>
-<h1>Foo</h1>
-<p>bar
-baz</p>
-</blockquote>
-.
-
-The spaces after the `>` characters can be omitted:
-
-.
-># Foo
->bar
-> baz
-.
-<blockquote>
-<h1>Foo</h1>
-<p>bar
-baz</p>
-</blockquote>
-.
-
-The `>` characters can be indented 1-3 spaces:
-
-.
-   > # Foo
-   > bar
- > baz
-.
-<blockquote>
-<h1>Foo</h1>
-<p>bar
-baz</p>
-</blockquote>
-.
-
-Four spaces gives us a code block:
-
-.
-    > # Foo
-    > bar
-    > baz
-.
-<pre><code>&gt; # Foo
-&gt; bar
-&gt; baz
-</code></pre>
-.
-
-The Laziness clause allows us to omit the `>` before a
-paragraph continuation line:
-
-.
-> # Foo
-> bar
-baz
-.
-<blockquote>
-<h1>Foo</h1>
-<p>bar
-baz</p>
-</blockquote>
-.
-
-A block quote can contain some lazy and some non-lazy
-continuation lines:
-
-.
-> bar
-baz
-> foo
-.
-<blockquote>
-<p>bar
-baz
-foo</p>
-</blockquote>
-.
-
-Laziness only applies to lines that are continuations of
-paragraphs. Lines containing characters or indentation that indicate
-block structure cannot be lazy.
-
-.
-> foo
----
-.
-<blockquote>
-<p>foo</p>
-</blockquote>
-<hr />
-.
-
-.
-> - foo
-- bar
-.
-<blockquote>
-<ul>
-<li>foo</li>
-</ul>
-</blockquote>
-<ul>
-<li>bar</li>
-</ul>
-.
-
-.
->     foo
-    bar
-.
-<blockquote>
-<pre><code>foo
-</code></pre>
-</blockquote>
-<pre><code>bar
-</code></pre>
-.
-
-.
-> ```
-foo
-```
-.
-<blockquote>
-<pre><code></code></pre>
-</blockquote>
-<p>foo</p>
-<pre><code></code></pre>
-.
-
-A block quote can be empty:
-
-.
->
-.
-<blockquote>
-</blockquote>
-.
-
-.
->
->  
-> 
-.
-<blockquote>
-</blockquote>
-.
-
-A block quote can have initial or final blank lines:
-
-.
->
-> foo
->  
-.
-<blockquote>
-<p>foo</p>
-</blockquote>
-.
-
-A blank line always separates block quotes:
-
-.
-> foo
-
-> bar
-.
-<blockquote>
-<p>foo</p>
-</blockquote>
-<blockquote>
-<p>bar</p>
-</blockquote>
-.
-
-(Most current Markdown implementations, including John Gruber's
-original `Markdown.pl`, will parse this example as a single block quote
-with two paragraphs.  But it seems better to allow the author to decide
-whether two block quotes or one are wanted.)
-
-Consecutiveness means that if we put these block quotes together,
-we get a single block quote:
-
-.
-> foo
-> bar
-.
-<blockquote>
-<p>foo
-bar</p>
-</blockquote>
-.
-
-To get a block quote with two paragraphs, use:
-
-.
-> foo
->
-> bar
-.
-<blockquote>
-<p>foo</p>
-<p>bar</p>
-</blockquote>
-.
-
-Block quotes can interrupt paragraphs:
-
-.
-foo
-> bar
-.
-<p>foo</p>
-<blockquote>
-<p>bar</p>
-</blockquote>
-.
-
-In general, blank lines are not needed before or after block
-quotes:
-
-.
-> aaa
-***
-> bbb
-.
-<blockquote>
-<p>aaa</p>
-</blockquote>
-<hr />
-<blockquote>
-<p>bbb</p>
-</blockquote>
-.
-
-However, because of laziness, a blank line is needed between
-a block quote and a following paragraph:
-
-.
-> bar
-baz
-.
-<blockquote>
-<p>bar
-baz</p>
-</blockquote>
-.
-
-.
-> bar
-
-baz
-.
-<blockquote>
-<p>bar</p>
-</blockquote>
-<p>baz</p>
-.
-
-.
-> bar
->
-baz
-.
-<blockquote>
-<p>bar</p>
-</blockquote>
-<p>baz</p>
-.
-
-It is a consequence of the Laziness rule that any number
-of initial `>`s may be omitted on a continuation line of a
-nested block quote:
-
-.
-> > > foo
-bar
-.
-<blockquote>
-<blockquote>
-<blockquote>
-<p>foo
-bar</p>
-</blockquote>
-</blockquote>
-</blockquote>
-.
-
-.
->>> foo
-> bar
->>baz
-.
-<blockquote>
-<blockquote>
-<blockquote>
-<p>foo
-bar
-baz</p>
-</blockquote>
-</blockquote>
-</blockquote>
-.
-
-When including an indented code block in a block quote,
-remember that the [block quote marker](#block-quote-marker) includes
-both the `>` and a following space.  So *five spaces* are needed after
-the `>`:
-
-.
->     code
-
->    not code
-.
-<blockquote>
-<pre><code>code
-</code></pre>
-</blockquote>
-<blockquote>
-<p>not code</p>
-</blockquote>
-.
-
-
-## List items
-
-A [list marker](#list-marker) <a id="list-marker"></a> is a
-[bullet list marker](#bullet-list-marker) or an [ordered list
-marker](#ordered-list-marker).
-
-A [bullet list marker](#bullet-list-marker) <a id="bullet-list-marker"></a>
-is a `-`, `+`, or `*` character.
-
-An [ordered list marker](#ordered-list-marker) <a id="ordered-list-marker"></a>
-is a sequence of one of more digits (`0-9`), followed by either a
-`.` character or a `)` character.
-
-The following rules define [list items](#list-item):
-
-1.  **Basic case.**  If a sequence of lines *Ls* constitute a sequence of
-    blocks *Bs* starting with a non-space character and not separated
-    from each other by more than one blank line, and *M* is a list
-    marker *M* of width *W* followed by 0 < *N* < 5 spaces, then the result
-    of prepending *M* and the following spaces to the first line of
-    *Ls*, and indenting subsequent lines of *Ls* by *W + N* spaces, is a
-    list item with *Bs* as its contents.  The type of the list item
-    (bullet or ordered) is determined by the type of its list marker.
-    If the list item is ordered, then it is also assigned a start
-    number, based on the ordered list marker.
-
-For example, let *Ls* be the lines
-
-.
-A paragraph
-with two lines.
-
-    indented code
-
-> A block quote.
-.
-<p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote>
-.
-
-And let *M* be the marker `1.`, and *N* = 2.  Then rule #1 says
-that the following is an ordered list item with start number 1,
-and the same contents as *Ls*:
-
-.
-1.  A paragraph
-    with two lines.
-
-        indented code
-
-    > A block quote.
-.
-<ol>
-<li><p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote></li>
-</ol>
-.
-
-The most important thing to notice is that the position of
-the text after the list marker determines how much indentation
-is needed in subsequent blocks in the list item.  If the list
-marker takes up two spaces, and there are three spaces between
-the list marker and the next nonspace character, then blocks
-must be indented five spaces in order to fall under the list
-item.
-
-Here are some examples showing how far content must be indented to be
-put under the list item:
-
-.
-- one
-
- two
-.
-<ul>
-<li>one</li>
-</ul>
-<p>two</p>
-.
-
-.
-- one
-
-  two
-.
-<ul>
-<li><p>one</p>
-<p>two</p></li>
-</ul>
-.
-
-.
- -    one
-
-     two
-.
-<ul>
-<li>one</li>
-</ul>
-<pre><code> two
-</code></pre>
-.
-
-.
- -    one
-
-      two
-.
-<ul>
-<li><p>one</p>
-<p>two</p></li>
-</ul>
-.
-
-It is tempting to think of this in terms of columns:  the continuation
-blocks must be indented at least to the column of the first nonspace
-character after the list marker.  However, that is not quite right.
-The spaces after the list marker determine how much relative indentation
-is needed.  Which column this indentation reaches will depend on
-how the list item is embedded in other constructions, as shown by
-this example:
-
-.
-   > > 1.  one
->>
->>     two
-.
-<blockquote>
-<blockquote>
-<ol>
-<li><p>one</p>
-<p>two</p></li>
-</ol>
-</blockquote>
-</blockquote>
-.
-
-Here `two` occurs in the same column as the list marker `1.`,
-but is actually contained in the list item, because there is
-sufficent indentation after the last containing blockquote marker.
-
-The converse is also possible.  In the following example, the word `two`
-occurs far to the right of the initial text of the list item, `one`, but
-it is not considered part of the list item, because it is not indented
-far enough past the blockquote marker:
-
-.
->>- one
->>
-  >  > two
-.
-<blockquote>
-<blockquote>
-<ul>
-<li>one</li>
-</ul>
-<p>two</p>
-</blockquote>
-</blockquote>
-.
-
-A list item may not contain blocks that are separated by more than
-one blank line.  Thus, two blank lines will end a list, unless the
-two blanks are contained in a [fenced code block](#fenced-code-block).
-
-.
-- foo
-
-  bar
-
-- foo
-
-
-  bar
-
-- ```
-  foo
-
-
-  bar
-  ```
-.
-<ul>
-<li><p>foo</p>
-<p>bar</p></li>
-<li><p>foo</p></li>
-</ul>
-<p>bar</p>
-<ul>
-<li><pre><code>foo
-
-
-bar
-</code></pre></li>
-</ul>
-.
-
-A list item may contain any kind of block:
-
-.
-1.  foo
-
-    ```
-    bar
-    ```
-
-    baz
-
-    > bam
-.
-<ol>
-<li><p>foo</p>
-<pre><code>bar
-</code></pre>
-<p>baz</p>
-<blockquote>
-<p>bam</p>
-</blockquote></li>
-</ol>
-.
-
-2.  **Item starting with indented code.**  If a sequence of lines *Ls*
-    constitute a sequence of blocks *Bs* starting with an indented code
-    block and not separated from each other by more than one blank line,
-    and *M* is a list marker *M* of width *W* followed by
-    one space, then the result of prepending *M* and the following
-    space to the first line of *Ls*, and indenting subsequent lines of
-    *Ls* by *W + 1* spaces, is a list item with *Bs* as its contents.
-    If a line is empty, then it need not be indented.  The type of the
-    list item (bullet or ordered) is determined by the type of its list
-    marker.  If the list item is ordered, then it is also assigned a
-    start number, based on the ordered list marker.
-
-An indented code block will have to be indented four spaces beyond
-the edge of the region where text will be included in the list item.
-In the following case that is 6 spaces:
-
-.
-- foo
-
-      bar
-.
-<ul>
-<li><p>foo</p>
-<pre><code>bar
-</code></pre></li>
-</ul>
-.
-
-And in this case it is 11 spaces:
-
-.
-  10.  foo
-
-           bar
-.
-<ol start="10">
-<li><p>foo</p>
-<pre><code>bar
-</code></pre></li>
-</ol>
-.
-
-If the *first* block in the list item is an indented code block,
-then by rule #2, the contents must be indented *one* space after the
-list marker:
-
-.
-    indented code
-
-paragraph
-
-    more code
-.
-<pre><code>indented code
-</code></pre>
-<p>paragraph</p>
-<pre><code>more code
-</code></pre>
-.
-
-.
-1.     indented code
-
-   paragraph
-
-       more code
-.
-<ol>
-<li><pre><code>indented code
-</code></pre>
-<p>paragraph</p>
-<pre><code>more code
-</code></pre></li>
-</ol>
-.
-
-Note that an additional space indent is interpreted as space
-inside the code block:
-
-.
-1.      indented code
-
-   paragraph
-
-       more code
-.
-<ol>
-<li><pre><code> indented code
-</code></pre>
-<p>paragraph</p>
-<pre><code>more code
-</code></pre></li>
-</ol>
-.
-
-Note that rules #1 and #2 only apply to two cases:  (a) cases
-in which the lines to be included in a list item begin with a nonspace
-character, and (b) cases in which they begin with an indented code
-block.  In a case like the following, where the first block begins with
-a three-space indent, the rules do not allow us to form a list item by
-indenting the whole thing and prepending a list marker:
-
-.
-   foo
-
-bar
-.
-<p>foo</p>
-<p>bar</p>
-.
-
-.
--    foo
-
-  bar
-.
-<ul>
-<li>foo</li>
-</ul>
-<p>bar</p>
-.
-
-This is not a significant restriction, because when a block begins
-with 1-3 spaces indent, the indentation can always be removed without
-a change in interpretation, allowing rule #1 to be applied.  So, in
-the above case:
-
-.
--  foo
-
-   bar
-.
-<ul>
-<li><p>foo</p>
-<p>bar</p></li>
-</ul>
-.
-
-
-3.  **Indentation.**  If a sequence of lines *Ls* constitutes a list item
-    according to rule #1 or #2, then the result of indenting each line
-    of *L* by 1-3 spaces (the same for each line) also constitutes a
-    list item with the same contents and attributes.  If a line is
-    empty, then it need not be indented.
-
-Indented one space:
-
-.
- 1.  A paragraph
-     with two lines.
-
-         indented code
-
-     > A block quote.
-.
-<ol>
-<li><p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote></li>
-</ol>
-.
-
-Indented two spaces:
-
-.
-  1.  A paragraph
-      with two lines.
-
-          indented code
-
-      > A block quote.
-.
-<ol>
-<li><p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote></li>
-</ol>
-.
-
-Indented three spaces:
-
-.
-   1.  A paragraph
-       with two lines.
-
-           indented code
-
-       > A block quote.
-.
-<ol>
-<li><p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote></li>
-</ol>
-.
-
-Four spaces indent gives a code block:
-
-.
-    1.  A paragraph
-        with two lines.
-
-            indented code
-
-        > A block quote.
-.
-<pre><code>1.  A paragraph
-    with two lines.
-
-        indented code
-
-    &gt; A block quote.
-</code></pre>
-.
-
-
-4.  **Laziness.**  If a string of lines *Ls* constitute a [list
-    item](#list-item) with contents *Bs*, then the result of deleting
-    some or all of the indentation from one or more lines in which the
-    next non-space character after the indentation is
-    [paragraph continuation text](#paragraph-continuation-text) is a
-    list item with the same contents and attributes.
-
-Here is an example with lazy continuation lines:
-
-.
-  1.  A paragraph
-with two lines.
-
-          indented code
-
-      > A block quote.
-.
-<ol>
-<li><p>A paragraph
-with two lines.</p>
-<pre><code>indented code
-</code></pre>
-<blockquote>
-<p>A block quote.</p>
-</blockquote></li>
-</ol>
-.
-
-Indentation can be partially deleted:
-
-.
-  1.  A paragraph
-    with two lines.
-.
-<ol>
-<li>A paragraph
-with two lines.</li>
-</ol>
-.
-
-These examples show how laziness can work in nested structures:
-
-.
-> 1. > Blockquote
-continued here.
-.
-<blockquote>
-<ol>
-<li><blockquote>
-<p>Blockquote
-continued here.</p>
-</blockquote></li>
-</ol>
-</blockquote>
-.
-
-.
-> 1. > Blockquote
-> continued here.
-.
-<blockquote>
-<ol>
-<li><blockquote>
-<p>Blockquote
-continued here.</p>
-</blockquote></li>
-</ol>
-</blockquote>
-.
-
-
-5.  **That's all.** Nothing that is not counted as a list item by rules
-    #1--4 counts as a [list item](#list-item).
-
-The rules for sublists follow from the general rules above.  A sublist
-must be indented the same number of spaces a paragraph would need to be
-in order to be included in the list item.
-
-So, in this case we need two spaces indent:
-
-.
-- foo
-  - bar
-    - baz
-.
-<ul>
-<li>foo
-<ul>
-<li>bar
-<ul>
-<li>baz</li>
-</ul></li>
-</ul></li>
-</ul>
-.
-
-One is not enough:
-
-.
-- foo
- - bar
-  - baz
-.
-<ul>
-<li>foo</li>
-<li>bar</li>
-<li>baz</li>
-</ul>
-.
-
-Here we need four, because the list marker is wider:
-
-.
-10) foo
-    - bar
-.
-<ol start="10">
-<li>foo
-<ul>
-<li>bar</li>
-</ul></li>
-</ol>
-.
-
-Three is not enough:
-
-.
-10) foo
-   - bar
-.
-<ol start="10">
-<li>foo</li>
-</ol>
-<ul>
-<li>bar</li>
-</ul>
-.
-
-A list may be the first block in a list item:
-
-.
-- - foo
-.
-<ul>
-<li><ul>
-<li>foo</li>
-</ul></li>
-</ul>
-.
-
-.
-1. - 2. foo
-.
-<ol>
-<li><ul>
-<li><ol start="2">
-<li>foo</li>
-</ol></li>
-</ul></li>
-</ol>
-.
-
-A list item may be empty:
-
-.
-- foo
--
-- bar
-.
-<ul>
-<li>foo</li>
-<li></li>
-<li>bar</li>
-</ul>
-.
-
-.
--
-.
-<ul>
-<li></li>
-</ul>
-.
-
-### Motivation
-
-John Gruber's Markdown spec says the following about list items:
-
-1. "List markers typically start at the left margin, but may be indented
-   by up to three spaces. List markers must be followed by one or more
-   spaces or a tab."
-
-2. "To make lists look nice, you can wrap items with hanging indents....
-   But if you don't want to, you don't have to."
-
-3. "List items may consist of multiple paragraphs. Each subsequent
-   paragraph in a list item must be indented by either 4 spaces or one
-   tab."
-
-4. "It looks nice if you indent every line of the subsequent paragraphs,
-   but here again, Markdown will allow you to be lazy."
-
-5. "To put a blockquote within a list item, the blockquote's `>`
-   delimiters need to be indented."
-
-6. "To put a code block within a list item, the code block needs to be
-   indented twice — 8 spaces or two tabs."
-
-These rules specify that a paragraph under a list item must be indented
-four spaces (presumably, from the left margin, rather than the start of
-the list marker, but this is not said), and that code under a list item
-must be indented eight spaces instead of the usual four.  They also say
-that a block quote must be indented, but not by how much; however, the
-example given has four spaces indentation.  Although nothing is said
-about other kinds of block-level content, it is certainly reasonable to
-infer that *all* block elements under a list item, including other
-lists, must be indented four spaces.  This principle has been called the
-*four-space rule*.
-
-The four-space rule is clear and principled, and if the reference
-implementation `Markdown.pl` had followed it, it probably would have
-become the standard.  However, `Markdown.pl` allowed paragraphs and
-sublists to start with only two spaces indentation, at least on the
-outer level.  Worse, its behavior was inconsistent: a sublist of an
-outer-level list needed two spaces indentation, but a sublist of this
-sublist needed three spaces.  It is not surprising, then, that different
-implementations of Markdown have developed very different rules for
-determining what comes under a list item.  (Pandoc and python-Markdown,
-for example, stuck with Gruber's syntax description and the four-space
-rule, while discount, redcarpet, marked, PHP Markdown, and others
-followed `Markdown.pl`'s behavior more closely.)
-
-Unfortunately, given the divergences between implementations, there
-is no way to give a spec for list items that will be guaranteed not
-to break any existing documents.  However, the spec given here should
-correctly handle lists formatted with either the four-space rule or
-the more forgiving `Markdown.pl` behavior, provided they are laid out
-in a way that is natural for a human to read.
-
-The strategy here is to let the width and indentation of the list marker
-determine the indentation necessary for blocks to fall under the list
-item, rather than having a fixed and arbitrary number.  The writer can
-think of the body of the list item as a unit which gets indented to the
-right enough to fit the list marker (and any indentation on the list
-marker).  (The laziness rule, #4, then allows continuation lines to be
-unindented if needed.)
-
-This rule is superior, we claim, to any rule requiring a fixed level of
-indentation from the margin.  The four-space rule is clear but
-unnatural. It is quite unintuitive that
-
-``` markdown
-- foo
-
-  bar
-
-  - baz
-```
-
-should be parsed as two lists with an intervening paragraph,
-
-``` html
-<ul>
-<li>foo</li>
-</ul>
-<p>bar</p>
-<ul>
-<li>baz</li>
-</ul>
-```
-
-as the four-space rule demands, rather than a single list,
-
-``` html
-<ul>
-<li><p>foo</p>
-<p>bar</p>
-<ul>
-<li>baz</li>
-</ul></li>
-</ul>
-```
-
-The choice of four spaces is arbitrary.  It can be learned, but it is
-not likely to be guessed, and it trips up beginners regularly.
-
-Would it help to adopt a two-space rule?  The problem is that such
-a rule, together with the rule allowing 1--3 spaces indentation of the
-initial list marker, allows text that is indented *less than* the
-original list marker to be included in the list item. For example,
-`Markdown.pl` parses
-
-``` markdown
-   - one
-
-  two
-```
-
-as a single list item, with `two` a continuation paragraph:
-
-``` html
-<ul>
-<li><p>one</p>
-<p>two</p></li>
-</ul>
-```
-
-and similarly
-
-``` markdown
->   - one
->
->  two
-```
-
-as
-
-``` html
-<blockquote>
-<ul>
-<li><p>one</p>
-<p>two</p></li>
-</ul>
-</blockquote>
-```
-
-This is extremely unintuitive.
-
-Rather than requiring a fixed indent from the margin, we could require
-a fixed indent (say, two spaces, or even one space) from the list marker (which
-may itself be indented).  This proposal would remove the last anomaly
-discussed.  Unlike the spec presented above, it would count the following
-as a list item with a subparagraph, even though the paragraph `bar`
-is not indented as far as the first paragraph `foo`:
-
-``` markdown
- 10. foo
-
-   bar  
-```
-
-Arguably this text does read like a list item with `bar` as a subparagraph,
-which may count in favor of the proposal.  However, on this proposal indented
-code would have to be indented six spaces after the list marker.  And this
-would break a lot of existing Markdown, which has the pattern:
-
-``` markdown
-1.  foo
-
-        indented code
-```
-
-where the code is indented eight spaces.  The spec above, by contrast, will
-parse this text as expected, since the code block's indentation is measured
-from the beginning of `foo`.
-
-The one case that needs special treatment is a list item that *starts*
-with indented code.  How much indentation is required in that case, since
-we don't have a "first paragraph" to measure from?  Rule #2 simply stipulates
-that in such cases, we require one space indentation from the list marker
-(and then the normal four spaces for the indented code).  This will match the
-four-space rule in cases where the list marker plus its initial indentation
-takes four spaces (a common case), but diverge in other cases.
-
-## Lists
-
-A [list](#list) <a id="list"></a> is a sequence of one or more
-list items [of the same type](#of-the-same-type).  The list items
-may be separated by single [blank lines](#blank-line), but two
-blank lines end all containing lists.
-
-Two list items are [of the same type](#of-the-same-type)
-<a id="of-the-same-type"></a> if they begin with a [list
-marker](#list-marker) of the same type.  Two list markers are of the
-same type if (a) they are bullet list markers using the same character
-(`-`, `+`, or `*`) or (b) they are ordered list numbers with the same
-delimiter (either `.` or `)`).
-
-A list is an [ordered list](#ordered-list) <a id="ordered-list"></a>
-if its constituent list items begin with
-[ordered list markers](#ordered-list-marker), and a [bullet
-list](#bullet-list) <a id="bullet-list"></a> if its constituent list
-items begin with [bullet list markers](#bullet-list-marker).
-
-The [start number](#start-number) <a id="start-number"></a>
-of an [ordered list](#ordered-list) is determined by the list number of
-its initial list item.  The numbers of subsequent list items are
-disregarded.
-
-A list is [loose](#loose) if it any of its constituent list items are
-separated by blank lines, or if any of its constituent list items
-directly contain two block-level elements with a blank line between
-them.  Otherwise a list is [tight](#tight).  (The difference in HTML output
-is that paragraphs in a loose with are wrapped in `<p>` tags, while
-paragraphs in a tight list are not.)
-
-Changing the bullet or ordered list delimiter starts a new list:
-
-.
-- foo
-- bar
-+ baz
-.
-<ul>
-<li>foo</li>
-<li>bar</li>
-</ul>
-<ul>
-<li>baz</li>
-</ul>
-.
-
-.
-1. foo
-2. bar
-3) baz
-.
-<ol>
-<li>foo</li>
-<li>bar</li>
-</ol>
-<ol start="3">
-<li>baz</li>
-</ol>
-.
-
-There can be blank lines between items, but two blank lines end
-a list:
-
-.
-- foo
-
-- bar
-
-
-- baz
-.
-<ul>
-<li><p>foo</p></li>
-<li><p>bar</p></li>
-</ul>
-<ul>
-<li>baz</li>
-</ul>
-.
-
-As illustrated above in the section on [list items](#list-item),
-two blank lines between blocks *within* a list item will also end a
-list:
-
-.
-- foo
-
-
-  bar
-- baz
-.
-<ul>
-<li>foo</li>
-</ul>
-<p>bar</p>
-<ul>
-<li>baz</li>
-</ul>
-.
-
-Indeed, two blank lines will end *all* containing lists:
-
-.
-- foo
-  - bar
-    - baz
-
-
-      bim
-.
-<ul>
-<li>foo
-<ul>
-<li>bar
-<ul>
-<li>baz</li>
-</ul></li>
-</ul></li>
-</ul>
-<pre><code>  bim
-</code></pre>
-.
-
-Thus, two blank lines can be used to separate consecutive lists of
-the same type, or to separate a list from an indented code block
-that would otherwise be parsed as a subparagraph of the final list
-item:
-
-.
-- foo
-- bar
-
-
-- baz
-- bim
-.
-<ul>
-<li>foo</li>
-<li>bar</li>
-</ul>
-<ul>
-<li>baz</li>
-<li>bim</li>
-</ul>
-.
-
-.
--   foo
-
-    notcode
-
--   foo
-
-
-    code
-.
-<ul>
-<li><p>foo</p>
-<p>notcode</p></li>
-<li><p>foo</p></li>
-</ul>
-<pre><code>code
-</code></pre>
-.
-
-List items need not be indented to the same level.  The following
-list items will be treated as items at the same list level,
-since none is indented enough to belong to the previous list
-item:
-
-.
-- a
- - b
-  - c
-   - d
-  - e
- - f
-- g
-.
-<ul>
-<li>a</li>
-<li>b</li>
-<li>c</li>
-<li>d</li>
-<li>e</li>
-<li>f</li>
-<li>g</li>
-</ul>
-.
-
-This is a loose list, because there is a blank line between
-two of the list items:
-
-.
-- a
-- b
-
-- c
-.
-<ul>
-<li><p>a</p></li>
-<li><p>b</p></li>
-<li><p>c</p></li>
-</ul>
-.
-
-So is this, with a empty second item:
-
-.
-* a
-*
-
-* c
-.
-<ul>
-<li><p>a</p></li>
-<li></li>
-<li><p>c</p></li>
-</ul>
-.
-
-These are loose lists, even though there is no space between the items,
-because one of the items directly contains two block-level elements
-with a blank line between them:
-
-.
-- a
-- b
-
-  c
-- d
-.
-<ul>
-<li><p>a</p></li>
-<li><p>b</p>
-<p>c</p></li>
-<li><p>d</p></li>
-</ul>
-.
-
-.
-- a
-- b
-
-  [ref]: /url
-- d
-.
-<ul>
-<li><p>a</p></li>
-<li><p>b</p></li>
-<li><p>d</p></li>
-</ul>
-.
-
-This is a tight list, because the blank lines are in a code block:
-
-.
-- a
-- ```
-  b
-
-
-  ```
-- c
-.
-<ul>
-<li>a</li>
-<li><pre><code>b
-
-
-</code></pre></li>
-<li>c</li>
-</ul>
-.
-
-This is a tight list, because the blank line is between two
-paragraphs of a sublist.  So the inner list is loose while
-the other list is tight:
-
-.
-- a
-  - b
-
-    c
-- d
-.
-<ul>
-<li>a
-<ul>
-<li><p>b</p>
-<p>c</p></li>
-</ul></li>
-<li>d</li>
-</ul>
-.
-
-This is a tight list, because the blank line is inside the
-block quote:
-
-.
-* a
-  > b
-  >
-* c
-.
-<ul>
-<li>a
-<blockquote>
-<p>b</p>
-</blockquote></li>
-<li>c</li>
-</ul>
-.
-
-This list is tight, because the consecutive block elements
-are not separated by blank lines:
-
-.
-- a
-  > b
-  ```
-  c
-  ```
-- d
-.
-<ul>
-<li>a
-<blockquote>
-<p>b</p>
-</blockquote>
-<pre><code>c
-</code></pre></li>
-<li>d</li>
-</ul>
-.
-
-A single-paragraph list is tight:
-
-.
-- a
-.
-<ul>
-<li>a</li>
-</ul>
-.
-
-.
-- a
-  - b
-.
-<ul>
-<li>a
-<ul>
-<li>b</li>
-</ul></li>
-</ul>
-.
-
-Here the outer list is loose, the inner list tight:
-
-.
-* foo
-  * bar
-
-  baz
-.
-<ul>
-<li><p>foo</p>
-<ul>
-<li>bar</li>
-</ul>
-<p>baz</p></li>
-</ul>
-.
-
-.
-- a
-  - b
-  - c
-
-- d
-  - e
-  - f
-.
-<ul>
-<li><p>a</p>
-<ul>
-<li>b</li>
-<li>c</li>
-</ul></li>
-<li><p>d</p>
-<ul>
-<li>e</li>
-<li>f</li>
-</ul></li>
-</ul>
-.
-
-# Inlines
-
-Inlines are parsed sequentially from the beginning of the character
-stream to the end (left to right, in left-to-right languages).
-Thus, for example, in
-
-.
-`hi`lo`
-.
-<p><code>hi</code>lo`</p>
-.
-
-`hi` is parsed as code, leaving the backtick at the end as a literal
-backtick.
-
-## Backslash escapes
-
-Any ASCII punctuation character may be backslash-escaped:
-
-.
-\!\"\#\$\%\&\'\(\)\*\+\,\-\.\/\:\;\<\=\>\?\@\[\\\]\^\_\`\{\|\}\~
-.
-<p>!&quot;#$%&amp;'()*+,-./:;&lt;=&gt;?@[\]^_`{|}~</p>
-.
-
-Backslashes before other characters are treated as literal
-backslashes:
-
-.
-\→\A\a\ \3\φ\«
-.
-<p>\   \A\a\ \3\φ\«</p>
-.
-
-Escaped characters are treated as regular characters and do
-not have their usual Markdown meanings:
-
-.
-\*not emphasized*
-\<br/> not a tag
-\[not a link](/foo)
-\`not code`
-1\. not a list
-\* not a list
-\# not a header
-\[foo]: /url "not a reference"
-.
-<p>*not emphasized*
-&lt;br/&gt; not a tag
-[not a link](/foo)
-`not code`
-1. not a list
-* not a list
-# not a header
-[foo]: /url &quot;not a reference&quot;</p>
-.
-
-If a backslash is itself escaped, the following character is not:
-
-.
-\\*emphasis*
-.
-<p>\<em>emphasis</em></p>
-.
-
-A backslash at the end of the line is a hard line break:
-
-.
-foo\
-bar
-.
-<p>foo<br />
-bar</p>
-.
-
-Backslash escapes do not work in code blocks, code spans, autolinks, or
-raw HTML:
-
-.
-`` \[\` ``
-.
-<p><code>\[\`</code></p>
-.
-
-.
-    \[\]
-.
-<pre><code>\[\]
-</code></pre>
-.
-
-.
-~~~
-\[\]
-~~~
-.
-<pre><code>\[\]
-</code></pre>
-.
-
-.
-<http://example.com?find=\*>
-.
-<p><a href="http://example.com?find=%5C*">http://example.com?find=\*</a></p>
-.
-
-.
-<a href="/bar\/)">
-.
-<p><a href="/bar\/)"></p>
-.
-
-But they work in all other contexts, including URLs and link titles,
-link references, and info strings in [fenced code
-blocks](#fenced-code-block):
-
-.
-[foo](/bar\* "ti\*tle")
-.
-<p><a href="/bar*" title="ti*tle">foo</a></p>
-.
-
-.
-[foo]
-
-[foo]: /bar\* "ti\*tle"
-.
-<p><a href="/bar*" title="ti*tle">foo</a></p>
-.
-
-.
-``` foo\+bar
-foo
-```
-.
-<pre><code class="language-foo+bar">foo
-</code></pre>
-.
-
-
-## Entities
-
-With the goal of making this standard as HTML-agnostic as possible, all
-valid HTML entities in any context are recognized as such and
-converted into unicode characters before they are stored in the AST.
-
-This allows implementations that target HTML output to trivially escape
-the entities when generating HTML, and simplifies the job of
-implementations targetting other languages, as these will only need to
-handle the unicode chars and need not be HTML-entity aware.
-
-[Named entities](#name-entities) <a id="named-entities"></a> consist of `&`
-+ any of the valid HTML5 entity names + `;`. The
-[following document](http://www.whatwg.org/specs/web-apps/current-work/multipage/entities.json)
-is used as an authoritative source of the valid entity names and their
-corresponding codepoints.
-
-Conforming implementations that target HTML don't need to generate
-entities for all the valid named entities that exist, with the exception
-of `"` (`&quot;`), `&` (`&amp;`), `<` (`&lt;`) and `>` (`&gt;`), which
-always need to be written as entities for security reasons.
-
-.
-&nbsp; &amp; &copy; &AElig; &Dcaron; &frac34; &HilbertSpace; &DifferentialD; &ClockwiseContourIntegral;
-.
-<p>  &amp; © Æ Ď ¾ ℋ ⅆ ∲</p>
-.
-
-[Decimal entities](#decimal-entities) <a id="decimal-entities"></a>
-consist of `&#` + a string of 1--8 arabic digits + `;`. Again, these
-entities need to be recognised and tranformed into their corresponding
-UTF8 codepoints. Invalid Unicode codepoints will be written as the
-"unknown codepoint" character (`0xFFFD`)
-
-.
-&#35; &#1234; &#992; &#98765432;
-.
-<p># Ӓ Ϡ �</p>
-.
-
-[Hexadecimal entities](#hexadecimal-entities) <a id="hexadecimal-entities"></a>
-consist of `&#` + either `X` or `x` + a string of 1-8 hexadecimal digits
-+ `;`. They will also be parsed and turned into their corresponding UTF8 values in the AST.
-
-.
-&#X22; &#XD06; &#xcab;
-.
-<p>&quot; ആ ಫ</p>
-.
-
-Here are some nonentities:
-
-.
-&nbsp &x; &#; &#x; &ThisIsWayTooLongToBeAnEntityIsntIt; &hi?;
-.
-<p>&amp;nbsp &amp;x; &amp;#; &amp;#x; &amp;ThisIsWayTooLongToBeAnEntityIsntIt; &amp;hi?;</p>
-.
-
-Although HTML5 does accept some entities without a trailing semicolon
-(such as `&copy`), these are not recognized as entities here, because it
-makes the grammar too ambiguous:
-
-.
-&copy
-.
-<p>&amp;copy</p>
-.
-
-Strings that are not on the list of HTML5 named entities are not
-recognized as entities either:
-
-.
-&MadeUpEntity;
-.
-<p>&amp;MadeUpEntity;</p>
-.
-
-Entities are recognized in any context besides code spans or
-code blocks, including raw HTML, URLs, [link titles](#link-title), and
-[fenced code block](#fenced-code-block) info strings:
-
-.
-<a href="&ouml;&ouml;.html">
-.
-<p><a href="&ouml;&ouml;.html"></p>
-.
-
-.
-[foo](/f&ouml;&ouml; "f&ouml;&ouml;")
-.
-<p><a href="/f%C3%B6%C3%B6" title="föö">foo</a></p>
-.
-
-.
-[foo]
-
-[foo]: /f&ouml;&ouml; "f&ouml;&ouml;"
-.
-<p><a href="/f%C3%B6%C3%B6" title="föö">foo</a></p>
-.
-
-.
-``` f&ouml;&ouml;
-foo
-```
-.
-<pre><code class="language-föö">foo
-</code></pre>
-.
-
-Entities are treated as literal text in code spans and code blocks:
-
-.
-`f&ouml;&ouml;`
-.
-<p><code>f&amp;ouml;&amp;ouml;</code></p>
-.
-
-.
-    f&ouml;f&ouml;
-.
-<pre><code>f&amp;ouml;f&amp;ouml;
-</code></pre>
-.
-
-## Code span
-
-A [backtick string](#backtick-string) <a id="backtick-string"></a>
-is a string of one or more backtick characters (`` ` ``) that is neither
-preceded nor followed by a backtick.
-
-A code span begins with a backtick string and ends with a backtick
-string of equal length.  The contents of the code span are the
-characters between the two backtick strings, with leading and trailing
-spaces and newlines removed, and consecutive spaces and newlines
-collapsed to single spaces.
-
-This is a simple code span:
-
-.
-`foo`
-.
-<p><code>foo</code></p>
-.
-
-Here two backticks are used, because the code contains a backtick.
-This example also illustrates stripping of leading and trailing spaces:
-
-.
-`` foo ` bar  ``
-.
-<p><code>foo ` bar</code></p>
-.
-
-This example shows the motivation for stripping leading and trailing
-spaces:
-
-.
-` `` `
-.
-<p><code>``</code></p>
-.
-
-Newlines are treated like spaces:
-
-.
-``
-foo
-``
-.
-<p><code>foo</code></p>
-.
-
-Interior spaces and newlines are collapsed into single spaces, just
-as they would be by a browser:
-
-.
-`foo   bar
-  baz`
-.
-<p><code>foo bar baz</code></p>
-.
-
-Q: Why not just leave the spaces, since browsers will collapse them
-anyway?  A:  Because we might be targeting a non-HTML format, and we
-shouldn't rely on HTML-specific rendering assumptions.
-
-(Existing implementations differ in their treatment of internal
-spaces and newlines.  Some, including `Markdown.pl` and
-`showdown`, convert an internal newline into a `<br />` tag.
-But this makes things difficult for those who like to hard-wrap
-their paragraphs, since a line break in the midst of a code
-span will cause an unintended line break in the output.  Others
-just leave internal spaces as they are, which is fine if only
-HTML is being targeted.)
-
-.
-`foo `` bar`
-.
-<p><code>foo `` bar</code></p>
-.
-
-Note that backslash escapes do not work in code spans. All backslashes
-are treated literally:
-
-.
-`foo\`bar`
-.
-<p><code>foo\</code>bar`</p>
-.
-
-Backslash escapes are never needed, because one can always choose a
-string of *n* backtick characters as delimiters, where the code does
-not contain any strings of exactly *n* backtick characters.
-
-Code span backticks have higher precedence than any other inline
-constructs except HTML tags and autolinks.  Thus, for example, this is
-not parsed as emphasized text, since the second `*` is part of a code
-span:
-
-.
-*foo`*`
-.
-<p>*foo<code>*</code></p>
-.
-
-And this is not parsed as a link:
-
-.
-[not a `link](/foo`)
-.
-<p>[not a <code>link](/foo</code>)</p>
-.
-
-But this is a link:
-
-.
-<http://foo.bar.`baz>`
-.
-<p><a href="http://foo.bar.%60baz">http://foo.bar.`baz</a>`</p>
-.
-
-And this is an HTML tag:
-
-.
-<a href="`">`
-.
-<p><a href="`">`</p>
-.
-
-When a backtick string is not closed by a matching backtick string,
-we just have literal backticks:
-
-.
-```foo``
-.
-<p>```foo``</p>
-.
-
-.
-`foo
-.
-<p>`foo</p>
-.
-
-## Emphasis and strong emphasis
-
-John Gruber's original [Markdown syntax
-description](http://daringfireball.net/projects/markdown/syntax#em) says:
-
-> Markdown treats asterisks (`*`) and underscores (`_`) as indicators of
-> emphasis. Text wrapped with one `*` or `_` will be wrapped with an HTML
-> `<em>` tag; double `*`'s or `_`'s will be wrapped with an HTML `<strong>`
-> tag.
-
-This is enough for most users, but these rules leave much undecided,
-especially when it comes to nested emphasis.  The original
-`Markdown.pl` test suite makes it clear that triple `***` and
-`___` delimiters can be used for strong emphasis, and most
-implementations have also allowed the following patterns:
-
-``` markdown
-***strong emph***
-***strong** in emph*
-***emph* in strong**
-**in strong *emph***
-*in emph **strong***
-```
-
-The following patterns are less widely supported, but the intent
-is clear and they are useful (especially in contexts like bibliography
-entries):
-
-``` markdown
-*emph *with emph* in it*
-**strong **with strong** in it**
-```
-
-Many implementations have also restricted intraword emphasis to
-the `*` forms, to avoid unwanted emphasis in words containing
-internal underscores.  (It is best practice to put these in code
-spans, but users often do not.)
-
-``` markdown
-internal emphasis: foo*bar*baz
-no emphasis: foo_bar_baz
-```
-
-The following rules capture all of these patterns, while allowing
-for efficient parsing strategies that do not backtrack:
-
-1.  A single `*` character [can open emphasis](#can-open-emphasis)
-    <a id="can-open-emphasis"></a> iff
-
-    (a) it is not part of a sequence of four or more unescaped `*`s,
-    (b) it is not followed by whitespace, and
-    (c) either it is not followed by a `*` character or it is
-        followed immediately by emphasis or strong emphasis.
-
-2.  A single `_` character [can open emphasis](#can-open-emphasis) iff
-
-    (a) it is not part of a sequence of four or more unescaped `_`s,
-    (b) it is not followed by whitespace,
-    (c) it is not preceded by an ASCII alphanumeric character, and
-    (d) either it is not followed by a `_` character or it is
-        followed immediately by emphasis or strong emphasis.
-
-3.  A single `*` character [can close emphasis](#can-close-emphasis)
-    <a id="can-close-emphasis"></a> iff
-
-    (a) it is not part of a sequence of four or more unescaped `*`s, and
-    (b) it is not preceded by whitespace.
-
-4.  A single `_` character [can close emphasis](#can-close-emphasis) iff
-
-    (a) it is not part of a sequence of four or more unescaped `_`s,
-    (b) it is not preceded by whitespace, and
-    (c) it is not followed by an ASCII alphanumeric character.
-
-5.  A double `**` [can open strong emphasis](#can-open-strong-emphasis)
-    <a id="can-open-strong-emphasis" ></a> iff
-
-    (a) it is not part of a sequence of four or more unescaped `*`s,
-    (b) it is not followed by whitespace, and
-    (c) either it is not followed by a `*` character or it is
-        followed immediately by emphasis.
-
-6.  A double `__` [can open strong emphasis](#can-open-strong-emphasis)
-    iff
-
-    (a) it is not part of a sequence of four or more unescaped `_`s,
-    (b) it is not followed by whitespace, and
-    (c) it is not preceded by an ASCII alphanumeric character, and
-    (d) either it is not followed by a `_` character or it is
-        followed immediately by emphasis.
-
-7.  A double `**` [can close strong emphasis](#can-close-strong-emphasis)
-    <a id="can-close-strong-emphasis" ></a> iff
-
-    (a) it is not part of a sequence of four or more unescaped `*`s, and
-    (b) it is not preceded by whitespace.
-
-8.  A double `__` [can close strong emphasis](#can-close-strong-emphasis)
-    iff
-
-    (a) it is not part of a sequence of four or more unescaped `_`s,
-    (b) it is not preceded by whitespace, and
-    (c) it is not followed by an ASCII alphanumeric character.
-
-9.  Emphasis begins with a delimiter that [can open
-    emphasis](#can-open-emphasis) and includes inlines parsed
-    sequentially until a delimiter that [can close
-    emphasis](#can-close-emphasis), and that uses the same
-    character (`_` or `*`) as the opening delimiter, is reached.
-
-10. Strong emphasis begins with a delimiter that [can open strong
-    emphasis](#can-open-strong-emphasis) and includes inlines parsed
-    sequentially until a delimiter that [can close strong
-    emphasis](#can-close-strong-emphasis), and that uses the
-    same character (`_` or `*`) as the opening delimiter, is reached.
-
-11. In case of ambiguity, strong emphasis takes precedence.  Thus,
-    `**foo**` is `<strong>foo</strong>`, not `<em><em>foo</em></em>`,
-    and `***foo***` is `<strong><em>foo</em></strong>`, not
-    `<em><strong>foo</strong></em>` or `<em><em><em>foo</em></em></em>`.
-
-These rules can be illustrated through a series of examples.
-
-Simple emphasis:
-
-.
-*foo bar*
-.
-<p><em>foo bar</em></p>
-.
-
-.
-_foo bar_
-.
-<p><em>foo bar</em></p>
-.
-
-Simple strong emphasis:
-
-.
-**foo bar**
-.
-<p><strong>foo bar</strong></p>
-.
-
-.
-__foo bar__
-.
-<p><strong>foo bar</strong></p>
-.
-
-Emphasis can continue over line breaks:
-
-.
-*foo
-bar*
-.
-<p><em>foo
-bar</em></p>
-.
-
-.
-_foo
-bar_
-.
-<p><em>foo
-bar</em></p>
-.
-
-.
-**foo
-bar**
-.
-<p><strong>foo
-bar</strong></p>
-.
-
-.
-__foo
-bar__
-.
-<p><strong>foo
-bar</strong></p>
-.
-
-Emphasis can contain other inline constructs:
-
-.
-*foo [bar](/url)*
-.
-<p><em>foo <a href="/url">bar</a></em></p>
-.
-
-.
-_foo [bar](/url)_
-.
-<p><em>foo <a href="/url">bar</a></em></p>
-.
-
-.
-**foo [bar](/url)**
-.
-<p><strong>foo <a href="/url">bar</a></strong></p>
-.
-
-.
-__foo [bar](/url)__
-.
-<p><strong>foo <a href="/url">bar</a></strong></p>
-.
-
-Symbols contained in other inline constructs will not
-close emphasis:
-
-.
-*foo [bar*](/url)
-.
-<p>*foo <a href="/url">bar*</a></p>
-.
-
-.
-_foo [bar_](/url)
-.
-<p>_foo <a href="/url">bar_</a></p>
-.
-
-.
-**<a href="**">
-.
-<p>**<a href="**"></p>
-.
-
-.
-__<a href="__">
-.
-<p>__<a href="__"></p>
-.
-
-.
-*a `*`*
-.
-<p><em>a <code>*</code></em></p>
-.
-
-.
-_a `_`_
-.
-<p><em>a <code>_</code></em></p>
-.
-
-.
-**a<http://foo.bar?q=**>
-.
-<p>**a<a href="http://foo.bar?q=**">http://foo.bar?q=**</a></p>
-.
-
-.
-__a<http://foo.bar?q=__>
-.
-<p>__a<a href="http://foo.bar?q=__">http://foo.bar?q=__</a></p>
-.
-
-This is not emphasis, because the opening delimiter is
-followed by white space:
-
-.
-and * foo bar*
-.
-<p>and * foo bar*</p>
-.
-
-.
-_ foo bar_
-.
-<p>_ foo bar_</p>
-.
-
-.
-and ** foo bar**
-.
-<p>and ** foo bar**</p>
-.
-
-.
-__ foo bar__
-.
-<p>__ foo bar__</p>
-.
-
-This is not emphasis, because the closing delimiter is
-preceded by white space:
-
-.
-and *foo bar *
-.
-<p>and *foo bar *</p>
-.
-
-.
-and _foo bar _
-.
-<p>and _foo bar _</p>
-.
-
-.
-and **foo bar **
-.
-<p>and **foo bar **</p>
-.
-
-.
-and __foo bar __
-.
-<p>and __foo bar __</p>
-.
-
-The rules imply that a sequence of four or more unescaped `*` or
-`_` characters will always be parsed as a literal string:
-
-.
-****hi****
-.
-<p>****hi****</p>
-.
-
-.
-_____hi_____
-.
-<p>_____hi_____</p>
-.
-
-.
-Sign here: _________
-.
-<p>Sign here: _________</p>
-.
-
-The rules also imply that there can be no empty emphasis or strong
-emphasis:
-
-.
-** is not an empty emphasis
-.
-<p>** is not an empty emphasis</p>
-.
-
-.
-**** is not an empty strong emphasis
-.
-<p>**** is not an empty strong emphasis</p>
-.
-
-To include `*` or `_` in emphasized sections, use backslash escapes
-or code spans:
-
-.
-*here is a \**
-.
-<p><em>here is a *</em></p>
-.
-
-.
-__this is a double underscore (`__`)__
-.
-<p><strong>this is a double underscore (<code>__</code>)</strong></p>
-.
-
-Or use the other emphasis character:
-
-.
-*_*
-.
-<p><em>_</em></p>
-.
-
-.
-_*_
-.
-<p><em>*</em></p>
-.
-
-.
-*__*
-.
-<p><em>__</em></p>
-.
-
-.
-_**_
-.
-<p><em>**</em></p>
-.
-
-`*` delimiters allow intra-word emphasis; `_` delimiters do not:
-
-.
-foo*bar*baz
-.
-<p>foo<em>bar</em>baz</p>
-.
-
-.
-foo_bar_baz
-.
-<p>foo_bar_baz</p>
-.
-
-.
-foo__bar__baz
-.
-<p>foo__bar__baz</p>
-.
-
-.
-_foo_bar_baz_
-.
-<p><em>foo_bar_baz</em></p>
-.
-
-.
-11*15*32
-.
-<p>11<em>15</em>32</p>
-.
-
-.
-11_15_32
-.
-<p>11_15_32</p>
-.
-
-Internal underscores will be ignored in underscore-delimited
-emphasis:
-
-.
-_foo_bar_baz_
-.
-<p><em>foo_bar_baz</em></p>
-.
-
-.
-__foo__bar__baz__
-.
-<p><strong>foo__bar__baz</strong></p>
-.
-
-The rules are sufficient for the following nesting patterns:
-
-.
-***foo bar***
-.
-<p><strong><em>foo bar</em></strong></p>
-.
-
-.
-___foo bar___
-.
-<p><strong><em>foo bar</em></strong></p>
-.
-
-.
-***foo** bar*
-.
-<p><em><strong>foo</strong> bar</em></p>
-.
-
-.
-___foo__ bar_
-.
-<p><em><strong>foo</strong> bar</em></p>
-.
-
-.
-***foo* bar**
-.
-<p><strong><em>foo</em> bar</strong></p>
-.
-
-.
-___foo_ bar__
-.
-<p><strong><em>foo</em> bar</strong></p>
-.
-
-.
-*foo **bar***
-.
-<p><em>foo <strong>bar</strong></em></p>
-.
-
-.
-_foo __bar___
-.
-<p><em>foo <strong>bar</strong></em></p>
-.
-
-.
-**foo *bar***
-.
-<p><strong>foo <em>bar</em></strong></p>
-.
-
-.
-__foo _bar___
-.
-<p><strong>foo <em>bar</em></strong></p>
-.
-
-.
-*foo **bar***
-.
-<p><em>foo <strong>bar</strong></em></p>
-.
-
-.
-_foo __bar___
-.
-<p><em>foo <strong>bar</strong></em></p>
-.
-
-.
-*foo *bar* baz*
-.
-<p><em>foo <em>bar</em> baz</em></p>
-.
-
-.
-_foo _bar_ baz_
-.
-<p><em>foo <em>bar</em> baz</em></p>
-.
-
-.
-**foo **bar** baz**
-.
-<p><strong>foo <strong>bar</strong> baz</strong></p>
-.
-
-.
-__foo __bar__ baz__
-.
-<p><strong>foo <strong>bar</strong> baz</strong></p>
-.
-
-.
-*foo **bar** baz*
-.
-<p><em>foo <strong>bar</strong> baz</em></p>
-.
-
-.
-_foo __bar__ baz_
-.
-<p><em>foo <strong>bar</strong> baz</em></p>
-.
-
-.
-**foo *bar* baz**
-.
-<p><strong>foo <em>bar</em> baz</strong></p>
-.
-
-.
-__foo _bar_ baz__
-.
-<p><strong>foo <em>bar</em> baz</strong></p>
-.
-
-.
-**foo, *bar*, baz**
-.
-<p><strong>foo, <em>bar</em>, baz</strong></p>
-.
-
-.
-__foo, _bar_, baz__
-.
-<p><strong>foo, <em>bar</em>, baz</strong></p>
-.
-
-But note:
-
-.
-*foo**bar**baz*
-.
-<p><em>foo</em><em>bar</em><em>baz</em></p>
-.
-
-.
-**foo*bar*baz**
-.
-<p><em><em>foo</em>bar</em>baz**</p>
-.
-
-The difference is that in the two preceding cases,
-the internal delimiters [can close emphasis](#can-close-emphasis),
-while in the cases with spaces, they cannot.
-
-Note that you cannot nest emphasis directly inside emphasis
-using the same delimeter, or strong emphasis directly inside
-strong emphasis:
-
-.
-**foo**
-.
-<p><strong>foo</strong></p>
-.
-
-.
-****foo****
-.
-<p>****foo****</p>
-.
-
-For these nestings, you need to switch delimiters:
-
-.
-*_foo_*
-.
-<p><em><em>foo</em></em></p>
-.
-
-.
-**__foo__**
-.
-<p><strong><strong>foo</strong></strong></p>
-.
-
-Note that a `*` followed by a `*` can close emphasis, and
-a `**` followed by a `*` can close strong emphasis (and
-similarly for `_` and `__`):
-
-.
-*foo**
-.
-<p><em>foo</em>*</p>
-.
-
-.
-*foo *bar**
-.
-<p><em>foo <em>bar</em></em></p>
-.
-
-.
-**foo***
-.
-<p><strong>foo</strong>*</p>
-.
-
-.
-***foo* bar***
-.
-<p><strong><em>foo</em> bar</strong>*</p>
-.
-
-.
-***foo** bar***
-.
-<p><em><strong>foo</strong> bar</em>**</p>
-.
-
-The following contains no strong emphasis, because the opening
-delimiter is closed by the first `*` before `bar`:
-
-.
-*foo**bar***
-.
-<p><em>foo</em><em>bar</em>**</p>
-.
-
-However, a string of four or more `****` can never close emphasis:
-
-.
-*foo****
-.
-<p>*foo****</p>
-.
-
-We retain symmetry in these cases:
-
-.
-*foo**
-
-**foo*
-.
-<p><em>foo</em>*</p>
-<p>*<em>foo</em></p>
-.
-
-.
-*foo *bar**
-
-**foo* bar*
-.
-<p><em>foo <em>bar</em></em></p>
-<p><em><em>foo</em> bar</em></p>
-.
-
-More cases with mismatched delimiters:
-
-.
-*bar***
-.
-<p><em>bar</em>**</p>
-.
-
-.
-***foo*
-.
-<p>**<em>foo</em></p>
-.
-
-.
-**bar***
-.
-<p><strong>bar</strong>*</p>
-.
-
-.
-***foo**
-.
-<p>*<strong>foo</strong></p>
-.
-
-.
-***foo *bar*
-.
-<p>***foo <em>bar</em></p>
-.
-
-## Links
-
-A link contains a [link label](#link-label) (the visible text),
-a [destination](#destination) (the URI that is the link destination),
-and optionally a [link title](#link-title).  There are two basic kinds
-of links in Markdown.  In [inline links](#inline-links) the destination
-and title are given immediately after the label.  In [reference
-links](#reference-links) the destination and title are defined elsewhere
-in the document.
-
-A [link label](#link-label) <a id="link-label"></a>  consists of
-
-- an opening `[`, followed by
-- zero or more backtick code spans, autolinks, HTML tags, link labels,
-  backslash-escaped ASCII punctuation characters, or non-`]` characters,
-  followed by
-- a closing `]`.
-
-These rules are motivated by the following intuitive ideas:
-
-- A link label is a container for inline elements.
-- The square brackets bind more tightly than emphasis markers,
-  but less tightly than `<>` or `` ` ``.
-- Link labels may contain material in matching square brackets.
-
-A [link destination](#link-destination) <a id="link-destination"></a>
-consists of either
-
-- a sequence of zero or more characters between an opening `<` and a
-  closing `>` that contains no line breaks or unescaped `<` or `>`
-  characters, or
-
-- a nonempty sequence of characters that does not include
-  ASCII space or control characters, and includes parentheses
-  only if (a) they are backslash-escaped or (b) they are part of
-  a balanced pair of unescaped parentheses that is not itself
-  inside a balanced pair of unescaped paretheses.
-
-A [link title](#link-title) <a id="link-title"></a>  consists of either
-
-- a sequence of zero or more characters between straight double-quote
-  characters (`"`), including a `"` character only if it is
-  backslash-escaped, or
-
-- a sequence of zero or more characters between straight single-quote
-  characters (`'`), including a `'` character only if it is
-  backslash-escaped, or
-
-- a sequence of zero or more characters between matching parentheses
-  (`(...)`), including a `)` character only if it is backslash-escaped.
-
-An [inline link](#inline-link) <a id="inline-link"></a>
-consists of a [link label](#link-label) followed immediately
-by a left parenthesis `(`, optional whitespace,
-an optional [link destination](#link-destination),
-an optional [link title](#link-title) separated from the link
-destination by whitespace, optional whitespace, and a right
-parenthesis `)`.  The link's text consists of the label (excluding
-the enclosing square brackets) parsed as inlines.  The link's
-URI consists of the link destination, excluding enclosing `<...>` if
-present, with backslash-escapes in effect as described above.  The
-link's title consists of the link title, excluding its enclosing
-delimiters, with backslash-escapes in effect as described above.
-
-Here is a simple inline link:
-
-.
-[link](/uri "title")
-.
-<p><a href="/uri" title="title">link</a></p>
-.
-
-The title may be omitted:
-
-.
-[link](/uri)
-.
-<p><a href="/uri">link</a></p>
-.
-
-Both the title and the destination may be omitted:
-
-.
-[link]()
-.
-<p><a href="">link</a></p>
-.
-
-.
-[link](<>)
-.
-<p><a href="">link</a></p>
-.
-
-
-If the destination contains spaces, it must be enclosed in pointy
-braces:
-
-.
-[link](/my uri)
-.
-<p>[link](/my uri)</p>
-.
-
-.
-[link](</my uri>)
-.
-<p><a href="/my%20uri">link</a></p>
-.
-
-The destination cannot contain line breaks, even with pointy braces:
-
-.
-[link](foo
-bar)
-.
-<p>[link](foo
-bar)</p>
-.
-
-One level of balanced parentheses is allowed without escaping:
-
-.
-[link]((foo)and(bar))
-.
-<p><a href="(foo)and(bar)">link</a></p>
-.
-
-However, if you have parentheses within parentheses, you need to escape
-or use the `<...>` form:
-
-.
-[link](foo(and(bar)))
-.
-<p>[link](foo(and(bar)))</p>
-.
-
-.
-[link](foo(and\(bar\)))
-.
-<p><a href="foo(and(bar))">link</a></p>
-.
-
-.
-[link](<foo(and(bar))>)
-.
-<p><a href="foo(and(bar))">link</a></p>
-.
-
-Parentheses and other symbols can also be escaped, as usual
-in Markdown:
-
-.
-[link](foo\)\:)
-.
-<p><a href="foo):">link</a></p>
-.
-
-URL-escaping should be left alone inside the destination, as all
-URL-escaped characters are also valid URL characters. HTML entities in
-the destination will be parsed into their UTF-8 codepoints, as usual, and
-optionally URL-escaped when written as HTML.
-
-.
-[link](foo%20b&auml;)
-.
-<p><a href="foo%20b%C3%A4">link</a></p>
-.
-
-Note that, because titles can often be parsed as destinations,
-if you try to omit the destination and keep the title, you'll
-get unexpected results:
-
-.
-[link]("title")
-.
-<p><a href="%22title%22">link</a></p>
-.
-
-Titles may be in single quotes, double quotes, or parentheses:
-
-.
-[link](/url "title")
-[link](/url 'title')
-[link](/url (title))
-.
-<p><a href="/url" title="title">link</a>
-<a href="/url" title="title">link</a>
-<a href="/url" title="title">link</a></p>
-.
-
-Backslash escapes and entities may be used in titles:
-
-.
-[link](/url "title \"&quot;")
-.
-<p><a href="/url" title="title &quot;&quot;">link</a></p>
-.
-
-Nested balanced quotes are not allowed without escaping:
-
-.
-[link](/url "title "and" title")
-.
-<p>[link](/url &quot;title &quot;and&quot; title&quot;)</p>
-.
-
-But it is easy to work around this by using a different quote type:
-
-.
-[link](/url 'title "and" title')
-.
-<p><a href="/url" title="title &quot;and&quot; title">link</a></p>
-.
-
-(Note:  `Markdown.pl` did allow double quotes inside a double-quoted
-title, and its test suite included a test demonstrating this.
-But it is hard to see a good rationale for the extra complexity this
-brings, since there are already many ways---backslash escaping,
-entities, or using a different quote type for the enclosing title---to
-write titles containing double quotes.  `Markdown.pl`'s handling of
-titles has a number of other strange features.  For example, it allows
-single-quoted titles in inline links, but not reference links.  And, in
-reference links but not inline links, it allows a title to begin with
-`"` and end with `)`.  `Markdown.pl` 1.0.1 even allows titles with no closing
-quotation mark, though 1.0.2b8 does not.  It seems preferable to adopt
-a simple, rational rule that works the same way in inline links and
-link reference definitions.)
-
-Whitespace is allowed around the destination and title:
-
-.
-[link](   /uri
-  "title"  )
-.
-<p><a href="/uri" title="title">link</a></p>
-.
-
-But it is not allowed between the link label and the
-following parenthesis:
-
-.
-[link] (/uri)
-.
-<p>[link] (/uri)</p>
-.
-
-Note that this is not a link, because the closing `]` occurs in
-an HTML tag:
-
-.
-[foo <bar attr="](baz)">
-.
-<p>[foo <bar attr="](baz)"></p>
-.
-
-
-There are three kinds of [reference links](#reference-link):
-<a id="reference-link"></a>
-
-A [full reference link](#full-reference-link) <a id="full-reference-link"></a>
-consists of a [link label](#link-label), optional whitespace, and
-another [link label](#link-label) that [matches](#matches) a
-[link reference definition](#link-reference-definition) elsewhere in the
-document.
-
-One label [matches](#matches) <a id="matches"></a>
-another just in case their normalized forms are equal.  To normalize a
-label, perform the *unicode case fold* and collapse consecutive internal
-whitespace to a single space.  If there are multiple matching reference
-link definitions, the one that comes first in the document is used.  (It
-is desirable in such cases to emit a warning.)
-
-The contents of the first link label are parsed as inlines, which are
-used as the link's text.  The link's URI and title are provided by the
-matching [link reference definition](#link-reference-definition).
-
-Here is a simple example:
-
-.
-[foo][bar]
-
-[bar]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-.
-
-The first label can contain inline content:
-
-.
-[*foo\!*][bar]
-
-[bar]: /url "title"
-.
-<p><a href="/url" title="title"><em>foo!</em></a></p>
-.
-
-Matching is case-insensitive:
-
-.
-[foo][BaR]
-
-[bar]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-.
-
-Unicode case fold is used:
-
-.
-[Толпой][Толпой] is a Russian word.
-
-[ТОЛПОЙ]: /url
-.
-<p><a href="/url">Толпой</a> is a Russian word.</p>
-.
-
-Consecutive internal whitespace is treated as one space for
-purposes of determining matching:
-
-.
-[Foo
-  bar]: /url
-
-[Baz][Foo bar]
-.
-<p><a href="/url">Baz</a></p>
-.
-
-There can be whitespace between the two labels:
-
-.
-[foo] [bar]
-
-[bar]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-.
-
-.
-[foo]
-[bar]
-
-[bar]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-.
-
-When there are multiple matching [link reference
-definitions](#link-reference-definition), the first is used:
-
-.
-[foo]: /url1
-
-[foo]: /url2
-
-[bar][foo]
-.
-<p><a href="/url1">bar</a></p>
-.
-
-Note that matching is performed on normalized strings, not parsed
-inline content.  So the following does not match, even though the
-labels define equivalent inline content:
-
-.
-[bar][foo\!]
-
-[foo!]: /url
-.
-<p>[bar][foo!]</p>
-.
-
-A [collapsed reference link](#collapsed-reference-link)
-<a id="collapsed-reference-link"></a> consists of a [link
-label](#link-label) that [matches](#matches) a [link reference
-definition](#link-reference-definition) elsewhere in the
-document, optional whitespace, and the string `[]`.  The contents of the
-first link label are parsed as inlines, which are used as the link's
-text.  The link's URI and title are provided by the matching reference
-link definition.  Thus, `[foo][]` is equivalent to `[foo][foo]`.
-
-.
-[foo][]
-
-[foo]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-.
-
-.
-[*foo* bar][]
-
-[*foo* bar]: /url "title"
-.
-<p><a href="/url" title="title"><em>foo</em> bar</a></p>
-.
-
-The link labels are case-insensitive:
-
-.
-[Foo][]
-
-[foo]: /url "title"
-.
-<p><a href="/url" title="title">Foo</a></p>
-.
-
-
-As with full reference links, whitespace is allowed
-between the two sets of brackets:
-
-.
-[foo] 
-[]
-
-[foo]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-.
-
-A [shortcut reference link](#shortcut-reference-link)
-<a id="shortcut-reference-link"></a> consists of a [link
-label](#link-label) that [matches](#matches) a [link reference
-definition](#link-reference-definition)  elsewhere in the
-document and is not followed by `[]` or a link label.
-The contents of the first link label are parsed as inlines,
-which are used as the link's text.  the link's URI and title
-are provided by the matching link reference definition.
-Thus, `[foo]` is equivalent to `[foo][]`.
-
-.
-[foo]
-
-[foo]: /url "title"
-.
-<p><a href="/url" title="title">foo</a></p>
-.
-
-.
-[*foo* bar]
-
-[*foo* bar]: /url "title"
-.
-<p><a href="/url" title="title"><em>foo</em> bar</a></p>
-.
-
-.
-[[*foo* bar]]
-
-[*foo* bar]: /url "title"
-.
-<p>[<a href="/url" title="title"><em>foo</em> bar</a>]</p>
-.
-
-The link labels are case-insensitive:
-
-.
-[Foo]
-
-[foo]: /url "title"
-.
-<p><a href="/url" title="title">Foo</a></p>
-.
-
-If you just want bracketed text, you can backslash-escape the
-opening bracket to avoid links:
-
-.
-\[foo]
-
-[foo]: /url "title"
-.
-<p>[foo]</p>
-.
-
-Note that this is a link, because link labels bind more tightly
-than emphasis:
-
-.
-[foo*]: /url
-
-*[foo*]
-.
-<p>*<a href="/url">foo*</a></p>
-.
-
-However, this is not, because link labels bind less
-tightly than code backticks:
-
-.
-[foo`]: /url
-
-[foo`]`
-.
-<p>[foo<code>]</code></p>
-.
-
-Link labels can contain matched square brackets:
-
-.
-[[[foo]]]
-
-[[[foo]]]: /url
-.
-<p><a href="/url">[[foo]]</a></p>
-.
-
-.
-[[[foo]]]
-
-[[[foo]]]: /url1
-[foo]: /url2
-.
-<p><a href="/url1">[[foo]]</a></p>
-.
-
-For non-matching brackets, use backslash escapes:
-
-.
-[\[foo]
-
-[\[foo]: /url
-.
-<p><a href="/url">[foo</a></p>
-.
-
-Full references take precedence over shortcut references:
-
-.
-[foo][bar]
-
-[foo]: /url1
-[bar]: /url2
-.
-<p><a href="/url2">foo</a></p>
-.
-
-In the following case `[bar][baz]` is parsed as a reference,
-`[foo]` as normal text:
-
-.
-[foo][bar][baz]
-
-[baz]: /url
-.
-<p>[foo]<a href="/url">bar</a></p>
-.
-
-Here, though, `[foo][bar]` is parsed as a reference, since
-`[bar]` is defined:
-
-.
-[foo][bar][baz]
-
-[baz]: /url1
-[bar]: /url2
-.
-<p><a href="/url2">foo</a><a href="/url1">baz</a></p>
-.
-
-Here `[foo]` is not parsed as a shortcut reference, because it
-is followed by a link label (even though `[bar]` is not defined):
-
-.
-[foo][bar][baz]
-
-[baz]: /url1
-[foo]: /url2
-.
-<p>[foo]<a href="/url1">bar</a></p>
-.
-
-
-## Images
-
-An (unescaped) exclamation mark (`!`) followed by a reference or
-inline link will be parsed as an image.  The link label will be
-used as the image's alt text, and the link title, if any, will
-be used as the image's title.
-
-.
-![foo](/url "title")
-.
-<p><img src="/url" alt="foo" title="title" /></p>
-.
-
-.
-![foo *bar*]
-
-[foo *bar*]: train.jpg "train & tracks"
-.
-<p><img src="train.jpg" alt="foo &lt;em&gt;bar&lt;/em&gt;" title="train &amp; tracks" /></p>
-.
-
-.
-![foo *bar*][]
-
-[foo *bar*]: train.jpg "train & tracks"
-.
-<p><img src="train.jpg" alt="foo &lt;em&gt;bar&lt;/em&gt;" title="train &amp; tracks" /></p>
-.
-
-.
-![foo *bar*][foobar]
-
-[FOOBAR]: train.jpg "train & tracks"
-.
-<p><img src="train.jpg" alt="foo &lt;em&gt;bar&lt;/em&gt;" title="train &amp; tracks" /></p>
-.
-
-.
-![foo](train.jpg)
-.
-<p><img src="train.jpg" alt="foo" /></p>
-.
-
-.
-My ![foo bar](/path/to/train.jpg  "title"   )
-.
-<p>My <img src="/path/to/train.jpg" alt="foo bar" title="title" /></p>
-.
-
-.
-![foo](<url>)
-.
-<p><img src="url" alt="foo" /></p>
-.
-
-.
-![](/url)
-.
-<p><img src="/url" alt="" /></p>
-.
-
-Reference-style:
-
-.
-![foo] [bar]
-
-[bar]: /url
-.
-<p><img src="/url" alt="foo" /></p>
-.
-
-.
-![foo] [bar]
-
-[BAR]: /url
-.
-<p><img src="/url" alt="foo" /></p>
-.
-
-Collapsed:
-
-.
-![foo][]
-
-[foo]: /url "title"
-.
-<p><img src="/url" alt="foo" title="title" /></p>
-.
-
-.
-![*foo* bar][]
-
-[*foo* bar]: /url "title"
-.
-<p><img src="/url" alt="&lt;em&gt;foo&lt;/em&gt; bar" title="title" /></p>
-.
-
-The labels are case-insensitive:
-
-.
-![Foo][]
-
-[foo]: /url "title"
-.
-<p><img src="/url" alt="Foo" title="title" /></p>
-.
-
-As with full reference links, whitespace is allowed
-between the two sets of brackets:
-
-.
-![foo] 
-[]
-
-[foo]: /url "title"
-.
-<p><img src="/url" alt="foo" title="title" /></p>
-.
-
-Shortcut:
-
-.
-![foo]
-
-[foo]: /url "title"
-.
-<p><img src="/url" alt="foo" title="title" /></p>
-.
-
-.
-![*foo* bar]
-
-[*foo* bar]: /url "title"
-.
-<p><img src="/url" alt="&lt;em&gt;foo&lt;/em&gt; bar" title="title" /></p>
-.
-
-.
-![[foo]]
-
-[[foo]]: /url "title"
-.
-<p><img src="/url" alt="[foo]" title="title" /></p>
-.
-
-The link labels are case-insensitive:
-
-.
-![Foo]
-
-[foo]: /url "title"
-.
-<p><img src="/url" alt="Foo" title="title" /></p>
-.
-
-If you just want bracketed text, you can backslash-escape the
-opening `!` and `[`:
-
-.
-\!\[foo]
-
-[foo]: /url "title"
-.
-<p>![foo]</p>
-.
-
-If you want a link after a literal `!`, backslash-escape the
-`!`:
-
-.
-\![foo]
-
-[foo]: /url "title"
-.
-<p>!<a href="/url" title="title">foo</a></p>
-.
-
-## Autolinks
-
-Autolinks are absolute URIs and email addresses inside `<` and `>`.
-They are parsed as links, with the URL or email address as the link
-label.
-
-A [URI autolink](#uri-autolink) <a id="uri-autolink"></a>
-consists of `<`, followed by an [absolute
-URI](#absolute-uri) not containing `<`, followed by `>`.  It is parsed
-as a link to the URI, with the URI as the link's label.
-
-An [absolute URI](#absolute-uri), <a id="absolute-uri"></a>
-for these purposes, consists of a [scheme](#scheme) followed by a colon (`:`)
-followed by zero or more characters other than ASCII whitespace and
-control characters, `<`, and `>`.  If the URI includes these characters,
-you must use percent-encoding (e.g. `%20` for a space).
-
-The following [schemes](#scheme) <a id="scheme"></a>
-are recognized (case-insensitive):
-`coap`, `doi`, `javascript`, `aaa`, `aaas`, `about`, `acap`, `cap`,
-`cid`, `crid`, `data`, `dav`, `dict`, `dns`, `file`, `ftp`, `geo`, `go`,
-`gopher`, `h323`, `http`, `https`, `iax`, `icap`, `im`, `imap`, `info`,
-`ipp`, `iris`, `iris.beep`, `iris.xpc`, `iris.xpcs`, `iris.lwz`, `ldap`,
-`mailto`, `mid`, `msrp`, `msrps`, `mtqp`, `mupdate`, `news`, `nfs`,
-`ni`, `nih`, `nntp`, `opaquelocktoken`, `pop`, `pres`, `rtsp`,
-`service`, `session`, `shttp`, `sieve`, `sip`, `sips`, `sms`, `snmp`,`
-soap.beep`, `soap.beeps`, `tag`, `tel`, `telnet`, `tftp`, `thismessage`,
-`tn3270`, `tip`, `tv`, `urn`, `vemmi`, `ws`, `wss`, `xcon`,
-`xcon-userid`, `xmlrpc.beep`, `xmlrpc.beeps`, `xmpp`, `z39.50r`,
-`z39.50s`, `adiumxtra`, `afp`, `afs`, `aim`, `apt`,` attachment`, `aw`,
-`beshare`, `bitcoin`, `bolo`, `callto`, `chrome`,` chrome-extension`,
-`com-eventbrite-attendee`, `content`, `cvs`,` dlna-playsingle`,
-`dlna-playcontainer`, `dtn`, `dvb`, `ed2k`, `facetime`, `feed`,
-`finger`, `fish`, `gg`, `git`, `gizmoproject`, `gtalk`, `hcp`, `icon`,
-`ipn`, `irc`, `irc6`, `ircs`, `itms`, `jar`, `jms`, `keyparc`, `lastfm`,
-`ldaps`, `magnet`, `maps`, `market`,` message`, `mms`, `ms-help`,
-`msnim`, `mumble`, `mvn`, `notes`, `oid`, `palm`, `paparazzi`,
-`platform`, `proxy`, `psyc`, `query`, `res`, `resource`, `rmi`, `rsync`,
-`rtmp`, `secondlife`, `sftp`, `sgn`, `skype`, `smb`, `soldat`,
-`spotify`, `ssh`, `steam`, `svn`, `teamspeak`, `things`, `udp`,
-`unreal`, `ut2004`, `ventrilo`, `view-source`, `webcal`, `wtai`,
-`wyciwyg`, `xfire`, `xri`, `ymsgr`.
-
-Here are some valid autolinks:
-
-.
-<http://foo.bar.baz>
-.
-<p><a href="http://foo.bar.baz">http://foo.bar.baz</a></p>
-.
-
-.
-<http://foo.bar.baz?q=hello&id=22&boolean>
-.
-<p><a href="http://foo.bar.baz?q=hello&amp;id=22&amp;boolean">http://foo.bar.baz?q=hello&amp;id=22&amp;boolean</a></p>
-.
-
-.
-<irc://foo.bar:2233/baz>
-.
-<p><a href="irc://foo.bar:2233/baz">irc://foo.bar:2233/baz</a></p>
-.
-
-Uppercase is also fine:
-
-.
-<MAILTO:FOO@BAR.BAZ>
-.
-<p><a href="MAILTO:FOO@BAR.BAZ">MAILTO:FOO@BAR.BAZ</a></p>
-.
-
-Spaces are not allowed in autolinks:
-
-.
-<http://foo.bar/baz bim>
-.
-<p>&lt;http://foo.bar/baz bim&gt;</p>
-.
-
-An [email autolink](#email-autolink) <a id="email-autolink"></a>
-consists of `<`, followed by an [email address](#email-address),
-followed by `>`.  The link's label is the email address,
-and the URL is `mailto:` followed by the email address.
-
-An [email address](#email-address), <a id="email-address"></a>
-for these purposes, is anything that matches
-the [non-normative regex from the HTML5
-spec](http://www.whatwg.org/specs/web-apps/current-work/multipage/forms.html#e-mail-state-%28type=email%29):
-
-    /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?
-    (?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/
-
-Examples of email autolinks:
-
-.
-<foo@bar.example.com>
-.
-<p><a href="mailto:foo@bar.example.com">foo@bar.example.com</a></p>
-.
-
-.
-<foo+special@Bar.baz-bar0.com>
-.
-<p><a href="mailto:foo+special@Bar.baz-bar0.com">foo+special@Bar.baz-bar0.com</a></p>
-.
-
-These are not autolinks:
-
-.
-<>
-.
-<p>&lt;&gt;</p>
-.
-
-.
-<heck://bing.bong>
-.
-<p>&lt;heck://bing.bong&gt;</p>
-.
-
-.
-< http://foo.bar >
-.
-<p>&lt; http://foo.bar &gt;</p>
-.
-
-.
-<foo.bar.baz>
-.
-<p>&lt;foo.bar.baz&gt;</p>
-.
-
-.
-<localhost:5001/foo>
-.
-<p>&lt;localhost:5001/foo&gt;</p>
-.
-
-.
-http://example.com
-.
-<p>http://example.com</p>
-.
-
-.
-foo@bar.example.com
-.
-<p>foo@bar.example.com</p>
-.
-
-## Raw HTML
-
-Text between `<` and `>` that looks like an HTML tag is parsed as a
-raw HTML tag and will be rendered in HTML without escaping.
-Tag and attribute names are not limited to current HTML tags,
-so custom tags (and even, say, DocBook tags) may be used.
-
-Here is the grammar for tags:
-
-A [tag name](#tag-name) <a id="tag-name"></a> consists of an ASCII letter
-followed by zero or more ASCII letters or digits.
-
-An [attribute](#attribute) <a id="attribute"></a> consists of whitespace,
-an **attribute name**, and an optional **attribute value
-specification**.
-
-An [attribute name](#attribute-name) <a id="attribute-name"></a>
-consists of an ASCII letter, `_`, or `:`, followed by zero or more ASCII
-letters, digits, `_`, `.`, `:`, or `-`.  (Note:  This is the XML
-specification restricted to ASCII.  HTML5 is laxer.)
-
-An [attribute value specification](#attribute-value-specification)
-<a id="attribute-value-specification"></a> consists of optional whitespace,
-a `=` character, optional whitespace, and an [attribute
-value](#attribute-value).
-
-An [attribute value](#attribute-value) <a id="attribute-value"></a>
-consists of an [unquoted attribute value](#unquoted-attribute-value),
-a [single-quoted attribute value](#single-quoted-attribute-value),
-or a [double-quoted attribute value](#double-quoted-attribute-value).
-
-An [unquoted attribute value](#unquoted-attribute-value)
-<a id="unquoted-attribute-value"></a> is a nonempty string of characters not
-including spaces, `"`, `'`, `=`, `<`, `>`, or `` ` ``.
-
-A [single-quoted attribute value](#single-quoted-attribute-value)
-<a id="single-quoted-attribute-value"></a> consists of `'`, zero or more
-characters not including `'`, and a final `'`.
-
-A [double-quoted attribute value](#double-quoted-attribute-value)
-<a id="double-quoted-attribute-value"></a> consists of `"`, zero or more
-characters not including `"`, and a final `"`.
-
-An [open tag](#open-tag) <a id="open-tag"></a> consists of a `<` character,
-a [tag name](#tag-name), zero or more [attributes](#attribute),
-optional whitespace, an optional `/` character, and a `>` character.
-
-A [closing tag](#closing-tag) <a id="closing-tag"></a> consists of the
-string `</`, a [tag name](#tag-name), optional whitespace, and the
-character `>`.
-
-An [HTML comment](#html-comment) <a id="html-comment"></a> consists of the
-string `<!--`, a string of characters not including the string `--`, and
-the string `-->`.
-
-A [processing instruction](#processing-instruction)
-<a id="processing-instruction"></a> consists of the string `<?`, a string
-of characters not including the string `?>`, and the string
-`?>`.
-
-A [declaration](#declaration) <a id="declaration"></a> consists of the
-string `<!`, a name consisting of one or more uppercase ASCII letters,
-whitespace, a string of characters not including the character `>`, and
-the character `>`.
-
-A [CDATA section](#cdata-section) <a id="cdata-section"></a> consists of
-the string `<![CDATA[`, a string of characters not including the string
-`]]>`, and the string `]]>`.
-
-An [HTML tag](#html-tag) <a id="html-tag"></a> consists of an [open
-tag](#open-tag), a [closing tag](#closing-tag), an [HTML
-comment](#html-comment), a [processing
-instruction](#processing-instruction), an [element type
-declaration](#element-type-declaration), or a [CDATA
-section](#cdata-section).
-
-Here are some simple open tags:
-
-.
-<a><bab><c2c>
-.
-<p><a><bab><c2c></p>
-.
-
-Empty elements:
-
-.
-<a/><b2/>
-.
-<p><a/><b2/></p>
-.
-
-Whitespace is allowed:
-
-.
-<a  /><b2
-data="foo" >
-.
-<p><a  /><b2
-data="foo" ></p>
-.
-
-With attributes:
-
-.
-<a foo="bar" bam = 'baz <em>"</em>'
-_boolean zoop:33=zoop:33 />
-.
-<p><a foo="bar" bam = 'baz <em>"</em>'
-_boolean zoop:33=zoop:33 /></p>
-.
-
-Illegal tag names, not parsed as HTML:
-
-.
-<33> <__>
-.
-<p>&lt;33&gt; &lt;__&gt;</p>
-.
-
-Illegal attribute names:
-
-.
-<a h*#ref="hi">
-.
-<p>&lt;a h*#ref=&quot;hi&quot;&gt;</p>
-.
-
-Illegal attribute values:
-
-.
-<a href="hi'> <a href=hi'>
-.
-<p>&lt;a href=&quot;hi'&gt; &lt;a href=hi'&gt;</p>
-.
-
-Illegal whitespace:
-
-.
-< a><
-foo><bar/ >
-.
-<p>&lt; a&gt;&lt;
-foo&gt;&lt;bar/ &gt;</p>
-.
-
-Missing whitespace:
-
-.
-<a href='bar'title=title>
-.
-<p>&lt;a href='bar'title=title&gt;</p>
-.
-
-Closing tags:
-
-.
-</a>
-</foo >
-.
-<p></a>
-</foo ></p>
-.
-
-Illegal attributes in closing tag:
-
-.
-</a href="foo">
-.
-<p>&lt;/a href=&quot;foo&quot;&gt;</p>
-.
-
-Comments:
-
-.
-foo <!-- this is a
-comment - with hyphen -->
-.
-<p>foo <!-- this is a
-comment - with hyphen --></p>
-.
-
-.
-foo <!-- not a comment -- two hyphens -->
-.
-<p>foo &lt;!-- not a comment -- two hyphens --&gt;</p>
-.
-
-Processing instructions:
-
-.
-foo <?php echo $a; ?>
-.
-<p>foo <?php echo $a; ?></p>
-.
-
-Declarations:
-
-.
-foo <!ELEMENT br EMPTY>
-.
-<p>foo <!ELEMENT br EMPTY></p>
-.
-
-CDATA sections:
-
-.
-foo <![CDATA[>&<]]>
-.
-<p>foo <![CDATA[>&<]]></p>
-.
-
-Entities are preserved in HTML attributes:
-
-.
-<a href="&ouml;">
-.
-<p><a href="&ouml;"></p>
-.
-
-Backslash escapes do not work in HTML attributes:
-
-.
-<a href="\*">
-.
-<p><a href="\*"></p>
-.
-
-.
-<a href="\"">
-.
-<p>&lt;a href=&quot;&quot;&quot;&gt;</p>
-.
-
-## Hard line breaks
-
-A line break (not in a code span or HTML tag) that is preceded
-by two or more spaces is parsed as a linebreak (rendered
-in HTML as a `<br />` tag):
-
-.
-foo  
-baz
-.
-<p>foo<br />
-baz</p>
-.
-
-For a more visible alternative, a backslash before the newline may be
-used instead of two spaces:
-
-.
-foo\
-baz
-.
-<p>foo<br />
-baz</p>
-.
-
-More than two spaces can be used:
-
-.
-foo       
-baz
-.
-<p>foo<br />
-baz</p>
-.
-
-Leading spaces at the beginning of the next line are ignored:
-
-.
-foo  
-     bar
-.
-<p>foo<br />
-bar</p>
-.
-
-.
-foo\
-     bar
-.
-<p>foo<br />
-bar</p>
-.
-
-Line breaks can occur inside emphasis, links, and other constructs
-that allow inline content:
-
-.
-*foo  
-bar*
-.
-<p><em>foo<br />
-bar</em></p>
-.
-
-.
-*foo\
-bar*
-.
-<p><em>foo<br />
-bar</em></p>
-.
-
-Line breaks do not occur inside code spans
-
-.
-`code  
-span`
-.
-<p><code>code span</code></p>
-.
-
-.
-`code\
-span`
-.
-<p><code>code\ span</code></p>
-.
-
-or HTML tags:
-
-.
-<a href="foo  
-bar">
-.
-<p><a href="foo  
-bar"></p>
-.
-
-.
-<a href="foo\
-bar">
-.
-<p><a href="foo\
-bar"></p>
-.
-
-## Soft line breaks
-
-A regular line break (not in a code span or HTML tag) that is not
-preceded by two or more spaces is parsed as a softbreak.  (A
-softbreak may be rendered in HTML either as a newline or as a space.
-The result will be the same in browsers. In the examples here, a
-newline will be used.)
-
-.
-foo
-baz
-.
-<p>foo
-baz</p>
-.
-
-Spaces at the end of the line and beginning of the next line are
-removed:
-
-.
-foo 
- baz
-.
-<p>foo
-baz</p>
-.
-
-A conforming parser may render a soft line break in HTML either as a
-line break or as a space.
-
-A renderer may also provide an option to render soft line breaks
-as hard line breaks.
-
-## Strings
-
-Any characters not given an interpretation by the above rules will
-be parsed as string content.
-
-.
-hello $.;'there
-.
-<p>hello $.;'there</p>
-.
-
-.
-Foo χρῆν
-.
-<p>Foo χρῆν</p>
-.
-
-Internal spaces are preserved verbatim:
-
-.
-Multiple     spaces
-.
-<p>Multiple     spaces</p>
-.
-
-<!-- END TESTS -->
-
-# Appendix A: A parsing strategy {-}
-
-## Overview {-}
-
-Parsing has two phases:
-
-1. In the first phase, lines of input are consumed and the block
-structure of the document---its division into paragraphs, block quotes,
-list items, and so on---is constructed.  Text is assigned to these
-blocks but not parsed. Link reference definitions are parsed and a
-map of links is constructed.
-
-2. In the second phase, the raw text contents of paragraphs and headers
-are parsed into sequences of Markdown inline elements (strings,
-code spans, links, emphasis, and so on), using the map of link
-references constructed in phase 1.
-
-## The document tree {-}
-
-At each point in processing, the document is represented as a tree of
-**blocks**.  The root of the tree is a `document` block.  The `document`
-may have any number of other blocks as **children**.  These children
-may, in turn, have other blocks as children.  The last child of a block
-is normally considered **open**, meaning that subsequent lines of input
-can alter its contents.  (Blocks that are not open are **closed**.)
-Here, for example, is a possible document tree, with the open blocks
-marked by arrows:
-
-``` tree
--> document
-  -> block_quote
-       paragraph
-         "Lorem ipsum dolor\nsit amet."
-    -> list (type=bullet tight=true bullet_char=-)
-         list_item
-           paragraph
-             "Qui *quodsi iracundia*"
-      -> list_item
-        -> paragraph
-             "aliquando id"
-```
-
-## How source lines alter the document tree {-}
-
-Each line that is processed has an effect on this tree.  The line is
-analyzed and, depending on its contents, the document may be altered
-in one or more of the following ways:
-
-1. One or more open blocks may be closed.
-2. One or more new blocks may be created as children of the
-   last open block.
-3. Text may be added to the last (deepest) open block remaining
-   on the tree.
-
-Once a line has been incorporated into the tree in this way,
-it can be discarded, so input can be read in a stream.
-
-We can see how this works by considering how the tree above is
-generated by four lines of Markdown:
-
-``` markdown
-> Lorem ipsum dolor
-sit amet.
-> - Qui *quodsi iracundia*
-> - aliquando id
-```
-
-At the outset, our document model is just
-
-``` tree
--> document
-```
-
-The first line of our text,
-
-``` markdown
-> Lorem ipsum dolor
-```
-
-causes a `block_quote` block to be created as a child of our
-open `document` block, and a `paragraph` block as a child of
-the `block_quote`.  Then the text is added to the last open
-block, the `paragraph`:
-
-``` tree
--> document
-  -> block_quote
-    -> paragraph
-         "Lorem ipsum dolor"
-```
-
-The next line,
-
-``` markdown
-sit amet.
-```
-
-is a "lazy continuation" of the open `paragraph`, so it gets added
-to the paragraph's text:
-
-``` tree
--> document
-  -> block_quote
-    -> paragraph
-         "Lorem ipsum dolor\nsit amet."
-```
-
-The third line,
-
-``` markdown
-> - Qui *quodsi iracundia*
-```
-
-causes the `paragraph` block to be closed, and a new `list` block
-opened as a child of the `block_quote`.  A `list_item` is also
-added as a child of the `list`, and a `paragraph` as a child of
-the `list_item`.  The text is then added to the new `paragraph`:
-
-``` tree
--> document
-  -> block_quote
-       paragraph
-         "Lorem ipsum dolor\nsit amet."
-    -> list (type=bullet tight=true bullet_char=-)
-      -> list_item
-        -> paragraph
-             "Qui *quodsi iracundia*"
-```
-
-The fourth line,
-
-``` markdown
-> - aliquando id
-```
-
-causes the `list_item` (and its child the `paragraph`) to be closed,
-and a new `list_item` opened up as child of the `list`.  A `paragraph`
-is added as a child of the new `list_item`, to contain the text.
-We thus obtain the final tree:
-
-``` tree
--> document
-  -> block_quote
-       paragraph
-         "Lorem ipsum dolor\nsit amet."
-    -> list (type=bullet tight=true bullet_char=-)
-         list_item
-           paragraph
-             "Qui *quodsi iracundia*"
-      -> list_item
-        -> paragraph
-             "aliquando id"
-```
-
-## From block structure to the final document {-}
-
-Once all of the input has been parsed, all open blocks are closed.
-
-We then "walk the tree," visiting every node, and parse raw
-string contents of paragraphs and headers as inlines.  At this
-point we have seen all the link reference definitions, so we can
-resolve reference links as we go.
-
-``` tree
-document
-  block_quote
-    paragraph
-      str "Lorem ipsum dolor"
-      softbreak
-      str "sit amet."
-    list (type=bullet tight=true bullet_char=-)
-      list_item
-        paragraph
-          str "Qui "
-          emph
-            str "quodsi iracundia"
-      list_item
-        paragraph
-          str "aliquando id"
-```
-
-Notice how the newline in the first paragraph has been parsed as
-a `softbreak`, and the asterisks in the first list item have become
-an `emph`.
-
-The document can be rendered as HTML, or in any other format, given
-an appropriate renderer.
-
-