Jinwen-XU
commented
2 years ago This is because that amsthm already defined the environment proof, and the key qed of create-theorem simply adds another Q.E.D. symbol to it without checking.
When you use create-theorem to define the proof environment, the main reason I can think of is to have a numbered version of proof. For this, you need to write something like the following:
\documentclass{article}
\usepackage{amsthm}
\usepackage{create-theorem}
\ExplSyntaxOn
\newcounter { proof }
\tl_new:N \l_mymodule_name_of_proof_tl
\CreateTheorem { proof_inner }
{
name = { heading = { \l_mymodule_name_of_proof_tl } },
create-starred-version,
style = remark,
qed,
shared-counter = proof,
}
\cs_undefine:c { proof }
\cs_undefine:c { endproof }
\NewDocumentEnvironment { proof } { O{\proofname} }
{
\tl_set:Nn \l_mymodule_name_of_proof_tl { #1 }
\begin { proof_inner }
}
{
\end { proof_inner }
}
\NewDocumentEnvironment { proof* } { O{\proofname} }
{
\tl_set:Nn \l_mymodule_name_of_proof_tl { #1 }
\begin { proof_inner* }
}
{
\end { proof_inner* }
}
\CreateTheorem { proof_mymodule_temp } { copy-existed = proof* }
\CreateTheorem { proof* } { copy-existed = proof }
\CreateTheorem { proof } { copy-existed = proof_mymodule_temp }
\SetTheoremBinding { proof* } { proof_inner }
\SetTheoremBinding { proof } { proof_inner* }
\ExplSyntaxOff
\begin{document}
\begin{proof}[foo]
some proof
\end{proof}
\begin{proof}
some proof
\end{proof}
\begin{proof*}[foo]
some proof
\end{proof*}
\SetTheorem{proof*}{number within = section}
\begin{proof*}
some proof
\end{proof*}
\end{document}The code is copied from my package projlib-theorem with only minor modifications. It defines an environment proof_inner (with its starred variant) with theorem style remark to mimic the default one (you are welcome to use your own style here), and with the name to be a variable which is latter used to define the real environments proof and proof*. The three lines of \CreateTheorem following it is to switch the environments proof and proof* so that proof is the usual unnumbered version and proof* is the numbered version (you can of course directly define them to work like this, I'm only writing this more complex version to demonstrate the feature). The \SetTheoremBinding lines are to ensure that user can directly write \SetTheorem{proof} rather than \SetTheorem{proof_inner}.
This may seem a little troublesome, but since you are also a class/package author this shouldn't be a problem ;)
atxy-blip
In recent tests I have found some issues with the
qedsetup ofcreate-theorem. To configure an environment with QED symbol, I have to loadamsthmto provide the commands\pushQED,\popQEDand\qed. However, this would cause multiple QED symbols generated.The MWE above would generate the result as follows. Note that this is actually the proof environment defined by
amsthmwith an additional QED symbol.The problem could be resolved by defining those commands mentioned by the package itself. The next MWE generates the desired result, where the
qedcommand is simply borrowed fromamsthm. There is still one problem with this approach, which is that the default value of qed key is not valid.It is also worth mentioning that not loading
amsthmwill also cause problems withnumberlessoption, which I have not found a proper solution so far.