[BUG] Lemma numbered correctly in appendix when using SIAM style file

[dpo]

Describe the bug

Lemma is numbered correctly in the appendix when using the SIAM style file.

To Reproduce: Minimal Working Example

% \documentclass{siamart220329}

\documentclass{article}
\usepackage{amssymb,amsmath,amsthm}
\newtheorem{lemma}{Lemma}[section]
\newtheorem{theorem}{Theorem}[section]
\newcommand{\lemmaautorefname}{Lemma}

\usepackage[createShortEnv, conf={one big link}]{proof-at-the-end}

\begin{document}

\section{Important Results}

\begin{lemmaE}[][end, restate]
  Life is not easy.
\end{lemmaE}

\begin{proofE}
  Immediate.
\end{proofE}

\begin{theoremE}[][end, restate]
  Life is hard.
\end{theoremE}

\begin{proofE}
  The result is direct.
\end{proofE}

\appendix

\section{Proofs}

\printProofs

\end{document}

Version
Output of latex --version:

$ latex --version
pdfTeX 3.141592653-2.6-1.40.25 (TeX Live 2023)
kpathsea version 6.3.5
Copyright 2023 Han The Thanh (pdfTeX) et al.
There is NO warranty.  Redistribution of this software is
covered by the terms of both the pdfTeX copyright and
the Lesser GNU General Public License.
For more information about these matters, see the file
named COPYING and the pdfTeX source.
Primary author of pdfTeX: Han The Thanh (pdfTeX) et al.
Compiled with libpng 1.6.39; using libpng 1.6.39
Compiled with zlib 1.2.13; using zlib 1.2.13
Compiled with xpdf version 4.04

Version of proof-at-the-end: 2022/02/07

Additional context

The lemma and theorem numbers are correct when compiling the document above. However, if you uncomment the first line and comment out the next five (in order to use the SIAM style file), the reference of the lemma is displayed as "Lemma A.1" instead of "Lemma 1.1", and the proof line says "Proof of Theorem 1.1" instead of "Proof of Lemma 1.1".

In addition, a "QED" symbol (a white square) is supposed to appear automatically upon \end{proof}, but it no longer does in the proofE environment.

Here is a link to their style file: https://epubs.siam.org/pb-assets/macros/standard/siamart220329.cls

Do you have any idea where the conflict could be?

Thank you in advance!

[tobiasBora]

Thanks for the report. I don't have a computer with me to test (and it might be hard for me to get one soon), but my guess is that SIAM might not be compatible with autoref that is used by default. You can use other engines to detect if it is a lemma or theorem, depending on the compatibility of SIAM, like cleveref. To use cleveref, just add `commandRef=Cref` in the options, and it will use \Cref{labelofthm} to call it. If you use cleveref, you might want to see its doc to customize the naming of thm etc…

[tobiasBora]

Ok, so I confirm that cref is more stable with SIAM and fix one of the two bugs, so load the package with commandRef=Cref:

\usepackage[
  createShortEnv,
  conf={one big link},
  %% Use Cref that seems more resilient than autoref in SIAM
  commandRef=Cref]{proof-at-the-end}

the second bug comes from thm-restate that I use internally. By default it only saves the equation counter, but we can ask it to save the current section number to avoid bad numbering with:

\makeatletter
\def\thmt@innercounters{section,equation} %% default is equation, we also need to save the section number in the restate
\makeatother

The whole code becomes:

\documentclass{siamart220329}

\usepackage[
  createShortEnv,
  conf={one big link},
  %% Use Cref that seems more resilient that autoref in SIAM
  commandRef=Cref]{proof-at-the-end}
\makeatletter
\def\thmt@innercounters{section,equation} %% default is equation, we also need to save the section number in the restate
\makeatother
\begin{document}

\section{Important Results}

\begin{lemmaE}[][end, restate]
  Life is not easy.
\end{lemmaE}

\begin{proofE}
  Immediate.
\end{proofE}

\begin{theoremE}[][end, restate]
  Life is hard.
\end{theoremE}

\begin{proofE}
  The result is direct.
\end{proofE}

\appendix

\section{Proofs}

\printProofs

\end{document}

Let me know if it works for you. If not, I will re-open it.

[dpo]

Thank you, that is a big improvement. There remains an issue with the "qed" symbol (a white square) that is inserted at the end of each proof in the SIAM style. When using your package, the symbol either disappears or appears in odd locations.

[tobiasBora]

This seems like the fault comes from the weird implementation of proof in SIAM. Notably, it seems to add a qed symbol only if there is a new line before the \end{proof}, but no empty line:

\begin{proof}[Proof of my theorem]
  This is with a new line before and a new line after.
\end{proof}

\begin{proof}[Proof of my theorem]Exactly identical, but with no space before, but one after.
\end{proof}

\begin{proof}[Proof of my theorem]Exactly identical, but with no space before nor after.\end{proof}

Gives:

The problem is that my library removes all new lines, because LaTeX seems to be fundamentally unable to detect/copy them without using verbatim environment, but these have other issues (notably, they can't be used inside other environments). The simpler solution is certainly to redefine the proof environment so that it always add a qed even if there is no line. You can maybe just copy the definition from amsthm (will try it later).

[tobiasBora]

Ok, so a simple workaround is to add \space before all \end{proofE}, like in:

\begin{proofE}
  Immediate.
  \space %% Otherwise, siamart does not add the qed symbol.
\end{proofE}

One can easily define a new environment proofEE that adds this space automatically (I am a bit reluctant to add this space by default in the library as this issue seems very related with how SIAM defines proof… or maybe I can automatically detect if I am in SIAM and add a space in that case). This gives this MWE:

\documentclass{siamart220329}

\usepackage[
  createShortEnv,
  conf={one big link},
  %% Use Cref that seems more resilient that autoref in SIAM
  commandRef=Cref]{proof-at-the-end}
\makeatletter
\def\thmt@innercounters{section,equation} %% default is equation, we also need to save the section number in the restate
\makeatother

%%% Defines a new environment that automatically adds the space
%%% to fix https://github.com/leo-colisson/proof-at-the-end/issues/14
\NewDocumentEnvironment{proofEE}{O{}+b}{%
  \begin{proofE}[#1]
    #2
    \space
  \end{proofE}
}{}


\begin{document}

\section{Important Results}

\begin{lemmaE}[][end, restate]
  Life is not easy.
\end{lemmaE}

\begin{proofEE}
  Immediate.
\end{proofEE}

\begin{theoremE}[][end, restate]
  Life is hard.
\end{theoremE}

\begin{proofEE}
  The result is direct.
\end{proofEE}

\appendix

\section{Proofs}

\printProofs

\end{document}

that produces:

Hopefully it will solve your issues. I don't know if there is a cleaner way that does not copy/paste the proof definition of amsthm.

[tobiasBora]

I will reopen until I document properly this case.

[tobiasBora]

Also, regarding the eratic position of the QED symbol, you might be interested by this question https://tex.stackexchange.com/questions/329159/erratic-position-of-qed-symbol-at-the-end-of-proof-environment-using-siam-templa

[dpo]

Thank you so much! We are 99.99% there. Here is one more glitch with the numbering of lemmas. I added a new section and a lemma under it:

\documentclass{siamart220329}

\usepackage[
  createShortEnv,
  conf={one big link},
  %% Use Cref that seems more resilient that autoref in SIAM
  commandRef=Cref]{proof-at-the-end}
\makeatletter
\def\thmt@innercounters{section,equation} %% default is equation, we also need to save the section number in the restate
\makeatother

%%% Defines a new environment that automatically adds the space
%%% to fix https://github.com/leo-colisson/proof-at-the-end/issues/14
\NewDocumentEnvironment{proofEE}{O{}+b}{%
  \begin{proofE}[#1]
    #2
    \space
  \end{proofE}
}{}


\begin{document}

\section{Important Results}

\begin{lemmaE}[][end, restate]
  Life is not easy.
\end{lemmaE}

\begin{proofEE}
  Immediate.
\end{proofEE}

\begin{theoremE}[][end, restate]
  Life is hard.
\end{theoremE}

\begin{proofEE}
  The result is direct.
\end{proofEE}

\section{A New Section}

\begin{lemmaE}[][end, restate]
  Life is definitely not easy.
\end{lemmaE}

\begin{proofEE}
  Still working on the proof.
\end{proofEE}

\appendix

\section{Proofs}

\printProofs

\end{document}

The new lemma has number 2.1. However, in the appendix, we see "Lemma 2.2 ... Proof of Lemma 2.1 ...".

[dpo]

The solution seems to be:

\makeatletter
\def\thmt@innercounters{section,equation,theorem} %% <-- add theorem counter here
\makeatother