自定义表格环境：自然演绎的证明表

Question

我想为自然演绎证明定义一个自定义环境，打印如下表格：

目前，我使用表格环境来编写这些证明：

    \documentclass{article}
    \begin{document}
    Some random text.
    \begin{center}
    \begin{tabular}{|c|c|c|c|c|c|}
    \hline
    \multicolumn{2}{|c|}{Stars} & Line & Formula & Reference & Rule \\ \hline
    $\star$ && 1 & $p \to q$ & -- & Hyp \\ \hline
    &$\star$& 2 & $p$ & -- & Hyp \\ \hline
    $\star$~~&$\star$ & 3 & $q$ & 1, 2 & E$\to$\\ \hline
    \end{tabular}
    \end{center}
    \noindent
    Yet again some random text.
    \end{document}

可以想象，以这种方式编写证明非常麻烦，所以我想拥有自己的环境。以下是我希望实现的一些功能：

• 你可以通过参数指定星形列的数量
• 每当你输入“*”时，LaTeX 都会打印\star
• 水平线会自动添加，因此您无需\hline每次都使用
• 行列会自动编号，因此您可以忽略它
• 如果指定的星形单元少于要求的星形单元，则剩余的星形单元将添加为空单元
• 环境默认居中
• 表格后的段落没有缩进。

例如，上面的证明在新环境中可能看起来像这样：

  \begin{ndproof}{2} % two star columns
   *& $p \to  q$ & -- & Hyp \\ % just one star cell specified, so second star cell empty
   &*& $p$ & -- & Hyp \\ 
   *&*&$p$ & 1, 2 & E$\to$ 
   \end{ndproof}

我是 LaTeX 新手，这个项目对我来说太大了。你们有人能帮我吗？也许你们还有让环境变得更好的想法！

Answer 1

这是一种可能的方法：

\documentclass{article}
\usepackage{array}

\ExplSyntaxOn

\newcounter{LN}
\newcommand{\LN}{\stepcounter{LN}\theLN}

\NewDocumentEnvironment{ndproof}{m}
 {
  \[
  \setcounter{LN}{0}
  \begin{tabular}
   {
    *{#1}{|c} | % stars
    >{\LN}c   | % line
    >{$}c<{$} | % formula
    c         | % reference
    c         | % rule
   }
  \hline
  \multicolumn{#1}{|c|}{Stars} &
  \multicolumn{1}{c|}{Line} &
  \multicolumn{1}{c|}{Formula} &
  Reference &
  Rule \\
  \hline
 }
 {
  \end{tabular}
  \]
  \ignorespacesafterend
 }

\NewDocumentCommand{\ndline}{mmmm}
 {
  \vitus_addstars:n { #1 } & & #2 & #3 & #4 \\ \hline
 }

\cs_new_protected:Nn \vitus_addstars:n
 {
  \seq_set_split:Nnn \l_tmpa_seq { } { #1 }
  \seq_set_map:NNn \l_tmpb_seq \l_tmpa_seq { \__vitus_star:n { ##1 } }
  \seq_use:Nn \l_tmpb_seq { & }
 }
\cs_new_protected:Nn \__vitus_star:n
 {
  \str_case:nn { #1 } { {-}{} {*}{$\star$} }
 }

\ExplSyntaxOff

\begin{document}

Some words preceding the proof, let's make it long enough so that
it splits across lines in order to well present the job.
\begin{ndproof}{2}
\ndline{*-}{p\to q}{--}{Hyp}
\ndline{-*}{p}{--}{Hyp}
\ndline{**}{q}{1, 2}{E$\to$}
\end{ndproof}
Some words following the proof, let's make it long enough so that
it splits across lines in order to well present the job.

\end{document}

对于星星，我认为有必要指定-是否不想将其排成一行。这也使输入更加一致。

修复了“星星”标题对于两列来说有点长的情况。

\documentclass{article}
\usepackage{array}

\ExplSyntaxOn

\newcounter{LN}
\NewDocumentCommand{\LN}{}{\stepcounter{LN}\theLN}

\NewDocumentEnvironment{ndproof}{m}
 {
  \[
  \setcounter{LN}{0}
  \settowidth{\dimen0}{Sterne}
  \setlength{\dimen0}{\dim_eval:n { \dimen0/2-\tabcolsep }}
  \use:x
   {
    \noexpand\begin{tabular}
     {
      *{#1}{|\int_compare:nTF{ #1=2 }{w{c}{\dimen0}}{c}} | % stars
      >{\LN}c   | % line
      >{$}c<{$} | % formula
      c         | % reference
      c         | % rule
     }
   }
  \hline
  \multicolumn{#1}{|c|}{Sterne} &
  \multicolumn{1}{c|}{Linie} &
  \multicolumn{1}{c|}{Formel} &
  Referenz &
  Regel \\
  \hline
 }
 {
  \end{tabular}
  \]
  \ignorespacesafterend
 }

\NewDocumentCommand{\ndline}{mmmm}
 {
  \vitus_addstars:n { #1 } & & #2 & #3 & #4 \\ \hline
 }

\cs_new_protected:Nn \vitus_addstars:n
 {
  \seq_set_split:Nnn \l_tmpa_seq { } { #1 }
  \seq_set_map:NNn \l_tmpb_seq \l_tmpa_seq { \__vitus_star:n { ##1 } }
  \seq_use:Nn \l_tmpb_seq { & }
 }
\cs_new_protected:Nn \__vitus_star:n
 {
  \str_case:nn { #1 } { {-}{} {*}{$\star$} }
 }

\ExplSyntaxOff

\begin{document}

Some words preceding the proof, let's make it long enough so that
it splits across lines in order to well present the job.
\begin{ndproof}{1}
\ndline{-}{p\to q}{--}{Hyp}
\ndline{-}{p}{--}{Hyp}
\ndline{*}{q}{1, 2}{E$\to$}
\end{ndproof}
Some words following the proof, let's make it long enough so that
it splits across lines in order to well present the job.
\begin{ndproof}{2}
\ndline{*-}{p\to q}{--}{Hyp}
\ndline{-*}{p}{--}{Hyp}
\ndline{**}{q}{1, 2}{E$\to$}
\end{ndproof}
Some words following the proof, let's make it long enough so that
it splits across lines in order to well present the job.
\begin{ndproof}{3}
\ndline{*--}{p\to q}{--}{Hyp}
\ndline{-*-}{p}{--}{Hyp}
\ndline{***}{q}{1, 2}{E$\to$}
\end{ndproof}
Some words following the proof, let's make it long enough so that
it splits across lines in order to well present the job.

\end{document}