修复列表问题

Question

让我们考虑以下 MWE：

\documentclass[letterpaper]{article}
\usepackage[marginparwidth=2in]{geometry}
\usepackage{amsmath,amssymb}
\usepackage{calc}
\usepackage{marginnote}
\usepackage{enumitem}

\newenvironment{test}[1][3.8ex]{%
\renewcommand{\theenumi}{\alph{enumi}}%
\renewcommand{\labelenumi}{\theenumi)}%
\renewcommand{\theenumii}{\roman{enumii}}%
\renewcommand{\labelenumii}{\theenumii)}%
\renewcommand{\marginparsep}{1em}%
\marginnote{List}[#1]%
  \list{}{%
  \setlength{\leftmargin}{0pt}%
  \setlength{\rightmargin}{0pt}%
  \setlength{\parfillskip}{0pt plus 2fil}%
  \setlength{\itemsep}{0pt}%
  \setlength{\topsep}{1ex}%
  \setlength{\partopsep}{0ex}
  \setlength{\parskip}{0pt}%
  \item\relax%
  }%
}{
  \endlist\ignorespacesafterend}

\reversemarginpar
\setlength{\parindent}{0pt}
\begin{document}    
     \begin{test}%
     Some random text
        \begin{enumerate}
        \item To answer the first part, we are going to find $A \cup B $ followed by the intersection of this with set $C$. Thus,
        \[(A \cup B ) \cap C =\{1,2,3,4,5,6,8\} \cap \{4,5,7\}= \{4,5\}\]
        \item In the second part, we will first find $B \cap C$ followed by the union of this with set $A$. Hence,
            \[A \cup (B \cap C)=\{1,2,3,4\} \cup \{5\} =\{1,2,3,4,5\}\]
        \end{enumerate}
        \end{test}
\end{document}

如果您注意到，枚举没有与边注水平对齐。如何实现这一点？对上述代码的任何改进都将不胜感激。我的方法是将topsep可能改为0ex但这还不够。A\vspace{<length>}是我的最后手段，但似乎太明显了。有几个问题：

1. 环境。我知道它不是最好的，但至少它可以编译
2. 用来[3.8ex]调整边注。不明白为什么它不能自然发生，如果可以，该如何补救。
3. 出现在 的a地方b。

我正在尝试创建一个示例\解决方案环境。

Answer 1

要制作 MWE，您需要剪掉保留问题的部分，这里是标签的叠印。您可以删除marginpar并enumitem开始：

\documentclass[letterpaper]{article}

\newenvironment{test}[1][3.8ex]{%
  \list{}{%
  \item\relax
  }%
}{%
  \endlist\ignorespacesafterend}

\begin{document}    
     \begin{test}%
     Some random text
        \begin{enumerate}
        \item To answer 
        \item In the 
        \end{enumerate}
        \end{test}
\end{document}

问题出在哪里（终于：-）一目了然：\item在错误的地方。它应该在列表环境的主体中，而不是在其参数中。

\documentclass[letterpaper]{article}

\newenvironment{test}[1][3.8ex]{%
  \list{}{%
  }%
  \item\relax
}{%
  \endlist\ignorespacesafterend}

\begin{document}    
     \begin{test}%
     Some random text
        \begin{enumerate}
        \item To answer 
        \item In the 
        \end{enumerate}
        \end{test}
\end{document}

---

将其放回并固定为不\marginparsep设置边注后，现在可以将其放置在（空）物品标签上，以便自然对齐而不需要任何偏移。\setlength\renewcommand

\documentclass[letterpaper]{article}
\usepackage[marginparwidth=2in]{geometry}
\usepackage{amsmath,amssymb}
\usepackage{calc}
\usepackage{marginnote}
\usepackage{enumitem}

\newenvironment{test}{%
\renewcommand{\theenumi}{\alph{enumi}}%
\renewcommand{\labelenumi}{\theenumi)}%
\renewcommand{\theenumii}{\roman{enumii}}%
\renewcommand{\labelenumii}{\theenumii)}%
\setlength{\marginparsep}{1em}%
  \list{}{%
  \setlength{\leftmargin}{0pt}%
  \setlength{\rightmargin}{0pt}%
  \setlength{\parfillskip}{0pt plus 2fil}%
  \setlength{\itemsep}{0pt}%
  \setlength{\topsep}{1ex}%
  \setlength{\partopsep}{0ex}
  \setlength{\parskip}{0pt}%
  }%
  \item\relax\leavevmode\marginnote{List}\ignorespaces
}{
  \endlist\ignorespacesafterend}

\reversemarginpar
\setlength{\parindent}{0pt}
\begin{document}    
     \begin{test}%
     Some random text
        \begin{enumerate}
        \item To answer the first part, we are going to find $A \cup B $ followed by the intersection of this with set $C$. Thus,
        \[(A \cup B ) \cap C =\{1,2,3,4,5,6,8\} \cap \{4,5,7\}= \{4,5\}\]
        \item In the second part, we will first find $B \cap C$ followed by the union of this with set $A$. Hence,
            \[A \cup (B \cap C)=\{1,2,3,4\} \cup \{5\} =\{1,2,3,4,5\}\]
        \end{enumerate}
        \end{test}
\end{document}