books/stacks/coding.tex

\input{preamble}

% OK, start here.
%
\begin{document}

\title{Coding Style}


\maketitle

\phantomsection
\label{section-phantom}

\tableofcontents

\section{List of style comments}
\label{section-style}

\noindent
These will be changed over time, but having some here now
will hopefully encourage a consistent LaTeX style.
We will call ``code\footnote{It is all Knuth's fault. See \cite{Knuth}.}''
the contents of the source files.

\begin{enumerate}
\item Keep all lines in all tex files to at most 80 characters.
\item Do not use indentation in the tex file. Use syntax highlighting in your
editor, instead of indentation, to visualize environments, etc.
\item Use
\begin{verbatim}
\medskip\noindent
\end{verbatim}
to start a new paragraph, and use
\begin{verbatim}
\noindent
\end{verbatim}
to start a new paragraph just after an environment.
\item Do not break the code for mathematical formulas across
lines if possible. If the complete code complete with enclosing
dollar signs does not fit on the line, then start with the first
dollar sign on the first character of the next line. If it still
does not fit, find a mathematically reasonable spot to break
the code.
\item Displayed math equations should be coded as follows
\begin{verbatim}
$$
...
...
$$
\end{verbatim}
In other words, start with a double dollar sign on a line by itself
and end similarly.
\item {\it Do not use any macros}. Rationale: This makes it easier
to read the tex file, and start editing an arbitrary part
without having to learn innumerable macros.
And it doesn't make it harder or more timeconsuming to write.
Of course the disadvantage is that the same mathematical object
may be TeXed differently in different places in the text, but
this should be easy to spot.
\item The theorem environments we use are:
``theorem'', ``proposition'', ``lemma'' (plain),
``definition'', ``example'', ``exercise'', ``situation'' (definition),
``remark'', ``remarks'' (remark). Of course there is also
a ``proof'' environment.
\item An environment ``foo'' should be coded as follows
\begin{verbatim}
\begin{foo}
...
...
\end{foo}
\end{verbatim}
similarly to the way displayed equations are coded.
\item Instead of a ``corollary'', just use ``lemma'' environment
since likely the result will be used to prove the next bigger
theorem anyway.
\item Directly following each lemma, proposition, or theorem
is the proof of said lemma, proposition, or theorem. No nested
proofs please.
\item The files preamble.tex, chapters.tex and fdl.tex are special
tex files. Apart from these, each tex file
has the following structure
\begin{verbatim}
\input{preamble}
\begin{document}
\title{Title}
\maketitle
\tableofcontents
...
...
\input{chapters}
\bibliography{my}
\bibliographystyle{amsalpha}
\end{document}
\end{verbatim}
\item Try to add labels to lemmas, propositions, theorems, and even
remarks, exercise, and other environments.
If labelling a lemma use something like
\begin{verbatim}
\begin{lemma}
\label{lemma-bar}
...
\end{lemma}
\end{verbatim}
Similarly for all other environments. In other words, the label
of a environment named ``foo'' starts with ``foo-''. In addition to
this please make all labels consist only of lower case letters,
digits, and the symbol ``-''.
\item Never refer to ``the lemma above'' (or proposition, etc).
Instead use:
\begin{verbatim}
Lemma \ref{lemma-bar} above
\end{verbatim}
This means that later
moving lemmas around is basically harmless.
\item Cross-file referencing. To reference a lemma labeled
``lemma-bar'' in the file foo.tex which has title
``Foo'', please use the following code
\begin{verbatim}
Foo, Lemma \ref{foo-lemma-bar}
\end{verbatim}
If this does not work, then take a look at the file
preamble.tex to find the correct expression to use.
This will produce the ``Foo, Lemma $<$link$>$'' in the
output file so it will be clear that the link points
out of the file.
\item If at all possible avoid forward references in proof
environments. (It should be possible to write an automated
test for this.)
\item Do not start any sentence with a mathematical symbol.
\item Do not have a sentence of the type ``This follows from
the following'' just before a lemma, proposition, or theorem.
Every sentence ends with a period.
\item State all hypotheses in each lemma, proposition, theorem.
This makes it easier for readers to see if a given
lemma, proposition, or theorem applies to their particular
problem.
\item Keep proofs short; less than 1 page in pdf or dvi.
You can always achieve this by splitting out the proof in lemmas
etc.
\item In a defining property foobar use
\begin{verbatim}
{\it foobar}
\end{verbatim}
in the code inside the definition environment.
Similarly if the definition occurs in the text of the document.
This will make it easier for the reader to see what it is
that is being defined.
\item Put any definition that will be used outside the section
it is in, in its own definition environment. Temporary definitions
may be made in the text. A tricky case is that of mathematical
constructions (which are often definitions involving interrelated
lemmas). Maybe a good solution is to have them in their own
short section so users can refer to the section instead of
a definition.
\item Do not number equations unless they are actually being
referenced somewhere in the text. We can always add labels later.
\item In statements of lemmas, propositions and theorems and
in proofs keep the sentences short. For example, instead of
``Let $R$ be a ring and let $M$ be an $R$-module.'' write
``Let $R$ be a ring. Let $M$ be an $R$-module.''. Rationale:
This makes it easier to parse the trickier parts of proofs and
statements.
\item Use the
\begin{verbatim}
\section
\end{verbatim}
command to make sections, but try to avoid using subsections
and subsubsections.
\item Avoid using complicated latex constructions.
\end{enumerate}





\input{chapters}

\bibliography{my}
\bibliographystyle{amsalpha}

\end{document}