☰

使用命令插入 \\ 与直接插入 \\ 的作用不同

tag-icon • tag-icon line-breaking
使用命令插入 \\ 与直接插入 \\ 的作用不同

我正在使用mathpartir包，我有一些代码（由 LyX 生成）将环境（我将其称为lines）放在中，并且只要其中有超过两行（以 分隔） \inferrule*，它似乎就会出现问题。我尝试了几种方法，但只要环境中有分隔两行，就无法编译任何东西。pdflatex\\\\lines

下面的代码正是我在Pastebin上上传的代码：http://pastebin.com/yBfm1zQ0

\documentclass{article}
\usepackage{mathpartir}
\begin{document}

\newcommand{\testa}{
  This is the intended use:
  \begin{mathpar}
    \inferrule*{
      1\\
      2
    }{
      3
    }
  \end{mathpar}
}

\newcommand{\testb}{
  % LaTeX Error: \begin{mathpar} on input line 68 ended by \end{lines}. [\testb]
  But (because the code is generated), I have an environment in the rule:
  \newenvironment{lines}{}{}
  \begin{mathpar}
    \inferrule*{
      \begin{lines}
        1\\
        2
      \end{lines}
    }{
      3
    }
  \end{mathpar}
}

\newcommand{\testc}{
  If \textbackslash\textbackslash is renamed \textbackslash{}plop, it works (or well, the output isn't what is expected but I know how to fix it and at least it compiles):

  \newcommand{\plop}{\\\relax}
  \newenvironment{lines}{}{}
  \begin{mathpar}
    \inferrule*{
      \begin{lines}
        1\plop
        2
      \end{lines}
    }{
      3
    }
  \end{mathpar}
}

\newcommand{\testd}{
  % LaTeX Error: \begin{mathpar} on input line 70 ended by \end{lines}. [\testd]
  And it's not the \textbackslash{}relax that fixes it:
  \newenvironment{lines}{}{}
  \begin{mathpar}
    \inferrule*{
      \begin{lines}
        1\\\relax
        2
      \end{lines}
    }{
      3
    }
  \end{mathpar}
}

% Line 66
%\testa
\testb
%\testc
%\testd


\end{document}

预先感谢您的帮助。

答案1

环境是一个组，所以你的代码就像

 {#1\\#2}

这是行不通的，你可以定义一个非环境来破坏分组，所以定义更像是

{}#1\\#2{}

有两个虚假的空组，而不是一个围绕整个事物的组。

\documentclass{article}
\usepackage{mathpartir}
\begin{document}

\newcommand{\testa}{
  This is the intended use:
  \begin{mathpar}
    \inferrule*{
      1\\
      2
    }{
      3
    }
  \end{mathpar}
}

\makeatletter
  \newenvironment{lines}{\endgroup}{\begingroup\def\@currenvir{lines}}
\makeatother
\newcommand{\testb}{
  % LaTeX Error: \begin{mathpar} on input line 68 ended by \end{lines}. [\testb]
  But (because the code is generated), I have an environment in the rule:
  \begin{mathpar}
    \inferrule*{
      \begin{lines}
        1\\
        2
      \end{lines}
    }{
      3
    }
  \end{mathpar}
}

\newcommand{\testc}{
  If \textbackslash\textbackslash is renamed \textbackslash{}plop, it works (or well, the output isn't what is expected but I know how to fix it and at least it compiles):

  \newcommand{\plop}{\\\relax}
  \newenvironment{lines}{}{}
  \begin{mathpar}
    \inferrule*{
      \begin{lines}
        1\plop
        2
      \end{lines}
    }{
      3
    }
  \end{mathpar}
}

\newcommand{\testd}{
  % LaTeX Error: \begin{mathpar} on input line 70 ended by \end{lines}. [\testd]
  And it's not the \textbackslash{}relax that fixes it:
  \newenvironment{lines}{}{}
  \begin{mathpar}
    \inferrule*{
      \begin{lines}
        1\\\relax
        2
      \end{lines}
    }{
      3
    }
  \end{mathpar}
}

% Line 66
%\testa
\testb
%\testc
%\testd


\end{document}

答案2

我找到了解决办法，但我不明白 >_<

\newcommand{\teste}{
  I finally found a fix. Apparently, \textbackslash{}inferrule* doesn't like having several things in its content so if you wrap everything in \{...\}, it works...
  \newenvironment{lines}{}{}
  \begin{mathpar}
    \inferrule*{
      {
        \begin{lines}
          1\\
          2
        \end{lines}
      }
    }{
      3
    }
  \end{mathpar}
}

最奇怪的是，如果两个 { 互相接触，} 也互相接触，就会失败 >_<

\newcommand{\teste}{
  I finally found a fix. Apparently, \textbackslash{}inferrule* doesn't like having several things in its content so if you wrap everything in \{...\}, it works...
  \newenvironment{lines}{}{}
  \begin{mathpar}
    \inferrule*{{
      \begin{lines}
        1\\
        2
      \end{lines}
    }}{
      3
    }
  \end{mathpar}
}

相关内容