如何使逻辑证明的行数添加括号？

Question

MWE 如下：

\documentclass{article}
\usepackage{amsmath,amsfonts,amssymb}
\usepackage{logicproof}
\usepackage{etoolbox}
%%%make logic proof lines ragged left%%%%%%%%%%%%%%%%%%%
\patchcmd{\logicproof}{\center}{\flushleft}{}{}
\patchcmd{\endlogicproof}{\endcenter}{\endflushleft}{}{}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\begin{document}
\begin{logicproof}{1}
        \forall x \, (P(x) \to Q(x)) & premise \label{cxy}\\
        \forall x \, P(x) & premise \\
        P(x_0) \to Q(x_0) & $\forall x \, \mathrm{e}$ 1 \\
        P(x_0) & $\forall x \, \mathrm{e}$ 2 \\
        Q(x_0) & $\to \mathrm{e}$ 3, 4 and so on \eqref{cxy}\\
        \forall x \, Q(x) & $\forall x \, \mathrm{i}$ 3--5
\end{logicproof}
\end{document}

它的输出是

我的问题是如何使逻辑证明的行数加括号，如（1）、（2）、（3）等？我尝试了几次，但不幸失败了。

欢迎任何回复！

Answer 1

保存校样中行号格式的宏是\lp@start@proof@line。您只需重新定义它：

\renewcommand{\lp@start@proof@line}{%
  \stepcounter{lp@line}%
  (\arabic{lp@line})%
  &%
  \lp@continue@proof@line%
}

\documentclass{article}
\usepackage{amsmath,amsfonts,amssymb}
\usepackage{logicproof}
\usepackage{etoolbox}
%%%make logic proof lines ragged left%%%%%%%%%%%%%%%%%%%
\patchcmd{\logicproof}{\center}{\flushleft}{}{}
\patchcmd{\endlogicproof}{\endcenter}{\endflushleft}{}{}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\makeatletter
\renewcommand{\lp@start@proof@line}{%
  \stepcounter{lp@line}%
  (\arabic{lp@line})%
  &%
  \lp@continue@proof@line%
}
\makeatother

\begin{document}
\begin{logicproof}{1}
        \forall x \, (P(x) \to Q(x)) & premise \label{cxy}\\
        \forall x \, P(x) & premise \\
        P(x_0) \to Q(x_0) & $\forall x \, \mathrm{e}$ 1 \\
        P(x_0) & $\forall x \, \mathrm{e}$ 2 \\
        Q(x_0) & $\to \mathrm{e}$ 3, 4 and so on \eqref{cxy}\\
        \forall x \, Q(x) & $\forall x \, \mathrm{i}$ 3--5
\end{logicproof}
\end{document}