\section{Extensions}

\subsection{Footnotes}

This is a footnote in history\footnote{\label{fn-1}
And it can have
lazy continuation lines and multiple paragraphs

If you indent one column after the footnote label start.

\begin{verbatim}
cb
\end{verbatim}

\begin{itemize}
\item{}
list item
ablc
\item{}
another item
\end{itemize}
} with mutiple references\textsuperscript{\ref{fn-1}}
and even \textsuperscript{\ref{fn-1}}

This is no longer the footnote.

Can we make footnotes in footnotes\footnote{\label{fn-2}
This gets tricky but I guess we could have a footnote\footnote{\label{fn-tricky}
The foot of the footnote. But that's not going to link back\textsuperscript{\ref{fn-2}}
} in
a footnote. Also footnote\textsuperscript{\ref{fn-1}} in footnotes\textsuperscript{\ref{fn-2}} is\footnote{\label{fn-3}} tricky for getting
all back references rendered correctly.

Second footnote
} ?

Not the footnote

Not the footnote but a reference to an empty footnote\textsuperscript{\ref{fn-3}}

Not a footnote [\textasciicircum{}]

[\textasciicircum{}]: not a footnote.

\subsection{Strikethrough}

The stroken \sout{\emph{emph}}.

Nesting the nest \sout{\emph{emph} \sout{stroke} \emph{emph \textbf{emph  \sout{strikeagain}}}}

There must be no blanks after the opener and before the closer. This
is \textasciitilde{}\textasciitilde{} not an opener and \textasciitilde{}\textasciitilde{}this won't open \sout{that does}.

\begin{itemize}
\item{}
Here we have \sout{stroken \texttt{code}}.
\item{}
Here we have \sout{nested \sout{stroken} ok}
\end{itemize}

\subsection{Math}

The inline \(\sqrt{x^2-1}\) equation.

There must be no blanks after the opener and before the closer. This
makes so you can donate \$5 or \$10 dollars here and there without problem.

There is no such think as nesting \(\sqrt{x^2-1}\)+3\(+3\). As usual
delimiters can be \$escaped\$ \(\sqrt{16\$}\)

Amazing, this is \href{https://example.org}{hyperlinked math \(3x^2\)}

The HTML renderer should be careful with \(a < b\) escapes.

Display math can be in \texttt{math} code blocks.
\[
\left( \sum_{k=1}^n a_k b_k \right)^2 < \Phi
\]

But it can also be in \[ \left( \sum_{k=1}^n
a_k b_k \right)^2 < \Phi \]

\subsection{List task items}

\begin{itemize}
\item{} \lbrack\phantom{x}\rbrack \enspace
Task open
\item{} \lbrack x\rbrack \enspace
Task done
\item{} \lbrack X\rbrack \enspace
Task done
\item{} \lbrack ✓\rbrack \enspace
Task done (U+2713, CHECK MARK)
\item{} \lbrack ✔\rbrack \enspace
Task done (U+2714, HEAVY CHECK MARK)
Indent
\item{}
Of course this can all be nested

\begin{itemize}
\item{} \lbrack 𐄂\rbrack \enspace
Task done (U+10102, AEGEAN CHECK MARK)
It will be done for sure.

\begin{verbatim}
code block
\end{verbatim}

Not a code block
\item{} \lbrack x\rbrack \enspace
Task done
\item{} \lbrack ~\rbrack \enspace
Task cancelled
Paragraphy
\item{} \lbrack ~\rbrack \enspace
Task canceled

\begin{verbatim}
we have a code block here too.
\end{verbatim}
\item{}
[x]Not a task
\item{}
[x] Not a task
\end{itemize}
\item{} \lbrack\phantom{x}\rbrack \enspace\item{} \lbrack\phantom{x}\rbrack \enspace
a

\begin{verbatim}
Code
\end{verbatim}

Not code
\item{} \lbrack\phantom{x}\rbrack \enspace
\begin{verbatim}
Code
\end{verbatim}

Not code
\end{itemize}

\subsection{Tables}

A sample table:

\bigskip
\begin{tabular}{llll}
\multicolumn{1}{c}{\bfseries{}Id}
 &
\multicolumn{1}{r}{\bfseries{}Name}
 &
\multicolumn{1}{l}{\bfseries{}Description}
 &
\multicolumn{1}{r}{\bfseries{}Link}
\\
\hline
\multicolumn{1}{c}{1}
 &
\multicolumn{1}{r}{OCaml}
 &
\multicolumn{1}{l}{The OCaml website}
 &
\multicolumn{1}{r}{\url{https://ocaml.org}}
\\
\multicolumn{1}{c}{2}
 &
\multicolumn{1}{r}{Haskell}
 &
\multicolumn{1}{l}{The Haskell website}
 &
\multicolumn{1}{r}{\url{https://haskell.org}}
\\
\multicolumn{1}{c}{3}
 &
\multicolumn{1}{r}{MDN Web docs}
 &
\multicolumn{1}{l}{Web dev docs}
 &
\multicolumn{1}{r}{\url{https://developer.mozilla.org/}}
\\
\multicolumn{1}{c}{4}
 &
\multicolumn{1}{r}{Wikipedia}
 &
\multicolumn{1}{l}{The Free Encyclopedia}
 &
\multicolumn{1}{r}{\url{https://wikipedia.org}}
\\
\hline
\end{tabular}
\bigskip

Testing these non separator pipes.

\bigskip
\begin{tabular}{lll}
{\bfseries{}Fancy}
 &
{\bfseries{}maybe}
 &
{\bfseries{}hu|glu}
\\
\hline
{\emph{a | b}}
 &
{\texttt{code |}}
 &
{\href{https://example.org}{bl|a}}
\\
{not | two cols}
 &
{\(\sqrt(x^2 - 1)\)}
 &
\\
\hline
\end{tabular}
\bigskip

A table with changing labels and alignement:

\bigskip
\begin{tabular}{ll}
{\bfseries{}h1}
 &
\multicolumn{1}{c}{\bfseries{}h2}
\\
\hline
{1}
 &
\multicolumn{1}{c}{2}
\\
\multicolumn{1}{l}{\bfseries{}h3}
 &
\multicolumn{1}{r}{\bfseries{}h4}
\\
\hline
\multicolumn{1}{l}{3}
 &
\multicolumn{1}{r}{4}
\\
\hline
\end{tabular}
\bigskip

A simple header less table with left and right aligned columns

\bigskip
\begin{tabular}{ll}
\hline
\multicolumn{1}{l}{1}
 &
\multicolumn{1}{r}{2}
\\
\hline
\end{tabular}
\bigskip

The simplest table:

\bigskip
\begin{tabular}{ll}
\hline
{1}
 &
{2}
\\
\hline
\end{tabular}
\bigskip

A header only table:

\bigskip
\begin{tabular}{ll}
\multicolumn{1}{c}{\bfseries{}h1}
 &
\multicolumn{1}{c}{\bfseries{}h2}
\\
\hline
\hline
\end{tabular}
\bigskip

Maximal number of columns all rows defines number of colums:

\bigskip
\begin{tabular}{llll}
\multicolumn{1}{l}{\bfseries{}h1}
 &
\multicolumn{1}{c}{\bfseries{}h2}
 &
\multicolumn{1}{r}{\bfseries{}h3}
 &
\\
\hline
\multicolumn{1}{l}{left}
 &
\multicolumn{1}{c}{center}
 &
\multicolumn{1}{r}{right}
 &
\\
\multicolumn{1}{l}{ha!}
 &
\multicolumn{1}{c}{four}
 &
\multicolumn{1}{r}{columns}
 &
{in fact}
\\
\multicolumn{1}{l}{}
 &
\multicolumn{1}{c}{}
 &
\multicolumn{1}{r}{}
 &
{}
\\
\multicolumn{1}{l}{}
 &
\multicolumn{1}{c}{}
 &
\multicolumn{1}{r}{}
 &
{a}
\\
\hline
\end{tabular}
\bigskip

Header less table:

\bigskip
\begin{tabular}{ll}
\hline
{header}
 &
{less}
\\
{this}
 &
{is}
\\
\hline
\end{tabular}
\bigskip

Another quoted header less table with aligement

\begin{quote}
\bigskip
\begin{tabular}{ll}
\hline
\multicolumn{1}{r}{header}
 &
\multicolumn{1}{r}{less}
\\
\multicolumn{1}{r}{again}
 &
\multicolumn{1}{r}{aligned}
\\
\hline
\end{tabular}
\bigskip
\end{quote}

This is an empty table with three columns:

\bigskip
\begin{tabular}{lll}
\hline
{}
 &
{}
 &
{}
\\
\hline
\end{tabular}
\bigskip

\subsection{Attributes}

\subsubsection{Block attributes}
% Attributes cannot be rendered in latex

This is a paragraph with the \texttt{my-id} is.
% Attributes cannot be rendered in latex

I have \texttt{your-id}, not mine
% Attributes cannot be rendered in latex

I have \texttt{his-id}, not mine, not yours
% Attributes cannot be rendered in latex

\paragraph{This is a title with the \texttt{.blue} class}
% Attributes cannot be rendered in latex

\begin{itemize}
\item{}
This is an item where \texttt{key} has value \texttt{value}.
\item{}
It is not possible to attach attributes to list items... yet
\end{itemize}
% Attributes cannot be rendered in latex

I'm a paragraph with many attributes
% Attributes cannot be rendered in latex

I have much more attribute than the previous one, since they stack
% Attributes cannot be rendered in latex

I have your id
% Attributes cannot be rendered in latex

I have a lot of class: \texttt{class1}, \texttt{class2}, \texttt{class3} and \texttt{class4}
% Attributes cannot be rendered in latex

Me too!
% Attributes cannot be rendered in latex

But spaceships matter.
% Attributes cannot be rendered in latex

Some word
% Attributes cannot be rendered in latex
% Attributes cannot be rendered in latex

\subsubsection{Inline attributes}

% Attributes omitted
 not a block attribute, but a standalone inline attribute, as I have content in the line.

In the middle of paragraphs, % Attributes omitted
 work.

Similarly, at the end, they work % Attributes omitted


Without specified delimitations, inline attributes are either % Attributes omitted
 or attached to the left-closest.

Inline attributes can % Attributes omitted
 including % Attributes omitted
.

Attributes can be nested: \href{example.com}{link % Attributes omitted
}, % Attributes omitted
, % Attributes omitted
.

Attributes can be attached without squares, for instance this has an
id. This \texttt{codeblock}! This \protect\includegraphics{as}. \href{work}{Links}. \textbf{Emphasis} and \emph{italic1} \emph{italic2}!

Testing \sout{strikethrough}.
% Attributes cannot be rendered in latex

\subsection{Title with an id}
% Attributes cannot be rendered in latex

\section{Title with an id}

\subsubsection{Attributes definition}

We can provide attributes% Unknown label definition type for a
 definition to avoid% Unknown label definition type for a
 cluttering% Unknown label definition type for cluttering
 a line with% Unknown label definition type for a
 attributes.
% Unknown Cmarkit block
% Unknown Cmarkit block

Attributes attached to attribute definition do nothing:

A b% Unknown label definition type for attr-attached-def
 c
% Unknown Cmarkit block

However, for link definition, they are present:

A \href{http://example.com}{b} c
