#Syntax reference

What HaTeX understands, grouped by what you're writing. For a working document that uses all of it, see examples/document/example.tex.

Anything not listed here is either ignored (layout commands, see the end of this page) or replaced by its argument text. The manual explains each feature in detail.

#Document

#Text

#Lists

\begin{itemize}  \item …  \end{itemize}
\begin{enumerate} \item … \end{enumerate}      % nested levels: 1. → a. → i.
\begin{description} \item[Term] … \end{description}
\item[custom] …                                  % custom label in itemize/enumerate

#Maths (KaTeX)

Whatever KaTeX supports works, including cases, pmatrix, \boldsymbol and \operatorname. Packages KaTeX doesn't have, such as siunitx, don't.

#Tables

\begin{table}[htbp]
  \centering
  \caption{Results.}\label{tab:main}
  \resizebox{\linewidth}{!}{%                  % shrink a wide table to the column
  \begin{tabular}{l|cc}
    \toprule
    \multirow{2}{*}{Method} & \multicolumn{2}{c}{Score} \\
    \cmidrule(lr){2-3}
     & A & B \\
    \midrule
    Ours & \textbf{1.0} & \underline{0.9} \\
    \rowcolor{yellow!20} Base & 0.5 & \cellcolor{red!10} 0.4 \\
    \bottomrule
  \end{tabular}}
\end{table}

• The column types l c r and | are supported, and p{…}, X and m{…} are treated as l.
• tabular, tabular*, tabularx and longtable all work.
• The rules are \toprule, \midrule, \bottomrule, \hline, \cline{2-3} and \cmidrule(lr){2-3}.
• \resizebox, \scalebox and \adjustbox around a table scale it down to fit (not below 55%, after which it scrolls).

#Figures

\begin{figure}[htbp]
  \centering
  \includegraphics[width=0.6\linewidth]{assets/plot.png}   % path relative to the page
  \caption{…}\label{fig:plot}
\end{figure}

\begin{figure}
  \begin{subfigure}[b]{0.45\linewidth} \includegraphics{a.png} \caption{A}\label{fig:a} \end{subfigure}
  \hfill
  \begin{subfigure}[b]{0.45\linewidth} \includegraphics{b.png} \caption{B}\label{fig:b} \end{subfigure}
  \caption{Both.}\label{fig:both}              % \ref{fig:a} → 2a
\end{figure}

• width= accepts x\linewidth (or \textwidth/\columnwidth) and absolute units, and height= and scale= also work.
• minipages side by side, each with its own \caption, are numbered separately.
• wrapfigure renders as an ordinary figure.
• Figures, tables and algorithms each keep their own counters.

#TikZ

\usetikzlibrary{arrows.meta,positioning}
\begin{figure}
  \centering
  \begin{tikzpicture}[node distance=15mm]
    \node[draw] (a) {A};
    \node[draw, right=of a] (b) {B};
    \draw[-Stealth] (a) -- node[above] {$f$} (b);
  \end{tikzpicture}
  \caption{…}\label{fig:ab}
\end{figure}

• tikzpicture and tikzcd work, and so does axis, which loads pgfplots.
• \tikzset, \pgfplotsset, \definecolor and \newcommand from the document are passed into the picture.
• Common libraries are detected from the code, and any others you declare with \usetikzlibrary.
• Labels must be ASCII. Maths inside $…$ is fine.
• The nn* styles for architecture diagrams are listed in the manual's TikZ chapter.

#Theorems and proofs

\newtheorem{hyp}{Hypothesis}                 % your own environment
\begin{theorem}[Name]\label{thm:x} … \end{theorem}
\begin{proof} … \end{proof}                  % ends with ∎

The built-in environments are theorem, lemma, corollary, proposition, definition, remark, example and proof. \newtheorem{a}[b]{…}, which shares b's counter, is supported.

#Algorithms

\begin{algorithm}
  \caption{Training}\label{alg:train}
  \begin{algorithmic}[1]                     % [1] numbers every line
    \Require data $x$
    \For{$t = 1, \dots, T$}
      \State $\theta \gets \theta - \eta \nabla L$ \Comment{step}
    \EndFor
    \State \Return $\theta$
  \end{algorithmic}
\end{algorithm}

The supported commands are \State, \Statex, \If/\ElsIf/\Else/\EndIf, \For/\ForAll/\EndFor, \While/\EndWhile, \Repeat/\Until, \Loop/\EndLoop, \Function/\Procedure with their \End…, \Require, \Ensure, \Return, \Call and \Comment.

#Code

\begin{lstlisting}[language=python] … \end{lstlisting}
\begin{minted}{js} … \end{minted}
\begin{verbatim} … \end{verbatim}
\verb|inline| \lstinline|inline| \mintinline{py}{inline}

Code is highlighted when Prism and the language's component are loaded, and shown as plain text otherwise.

#References and citations

Every link scrolls to its target and flashes it, and the URL doesn't change.

#Two columns

\documentclass[twocolumn]{article}   % the whole document; \twocolumn works too
\begin{figure*} … \end{figure*}      % spans both columns (so does table*)
\begin{multicols}{2}[Optional intro spanning the top]
  … \columnbreak …
\end{multicols}

• Columns appear once there is room: 50rem for a two-column document and 32rem for multicols.
• Headings, the abstract, figure* and table* span all columns. Everything else stays in its column: wide equations are scaled down to fit, pictures shrink, long code lines wrap, and wide tables scroll.

#Slides (beamer)

\documentclass[aspectratio=169]{beamer}
\title{Talk}  \subtitle{…}  \author{A \and B}  \institute{…}  \date{\today}
\begin{document}
\begin{frame} \titlepage \end{frame}
\begin{frame}{Outline} \tableofcontents \end{frame}
\section{Part one}
\begin{frame}[t]{Title}{Subtitle}
  \begin{columns}[T]
    \begin{column}{0.5\textwidth} \begin{itemize} \item<2-> … \end{itemize} \end{column}
    \begin{column}{0.5\textwidth} \begin{alertblock}{Careful} … \end{alertblock} \end{column}
  \end{columns}
\end{frame}
\end{document}

#Vertical Chinese

#Ignored on purpose

These produce nothing, but their arguments are still consumed so they don't leak into the text:

\tableofcontents \vspace \hspace \newpage \clearpage \pagestyle \setlength \setcounter \bibliographystyle \addbibresource (and \bibliography, \printbibliography without the bib/bbl option) \input \include \hypersetup \geometry \captionsetup \lstset \newenvironment \index \phantom and float placement options such as [htbp]. \title, \author and \date produce nothing in an article without \maketitle.