对齐节内容与运行节的第一行

Question

我目前在大学里使用以下布局进行每周练习：

\documentclass[a4paper, 12pt]{article}
\usepackage{titlesec}
\usepackage{lipsum}

% section title format and spacing
\titleformat{\subsection}[hang]{\sffamily\Large}{Exercise \arabic{section}.\arabic{subsection}}{0pt}{}[]
\titleformat{\subsubsection}[runin]{}{(\alph{subsubsection})}{0pt}{}[]
\titlespacing{\subsubsection}{0pt}{0.5em}{0.75em}

% subsubsection indentation
\let\svsubsubsection\subsubsection
\def\subsubsection{\leftskip1em\svsubsubsection}

\begin{document}
    \setcounter{section}{1}
    \subsection{}
    \subsubsection{}
        \lipsum[1-2]
    \subsubsection{}
        \[ some\ equation \]
    \subsection{}
\end{document}

如何将所有行与小节中第一行的开头对齐，如下图所示：

我怎样才能使\[ \]数学环境从小节的第一行开始？

Answer 1

您可以使用以下aligned环境：

代码：

\documentclass[a4paper, 12pt]{article}
\usepackage{titlesec}
\usepackage{lipsum}
\usepackage{mathtools}% <-- better to load this (it also loads amsmath)

% section title format and spacing
\titleformat{\subsection}[hang]{\sffamily\Large}{Exercise \arabic{section}.\arabic{subsection}}{0pt}{}[]
\titleformat{\subsubsection}[runin]{}{(\alph{subsubsection})}{0pt}{}[]
\titlespacing{\subsubsection}{0pt}{0.5em}{0.75em}

% subsubsection indentation
\let\svsubsubsection\subsubsection
\def\subsubsection{\leftskip1em\svsubsubsection}

\begin{document}
    \setcounter{section}{1}
    \subsection{}
    \subsubsection{}
        \lipsum[1-2]
    \subsubsection{}
    $\begin{aligned}[t]
        F &= ma \\
        E &= mc^2
     \end{aligned}$
    \subsection{}
\end{document}

Answer 2

enumerate我认为使用环境会更容易、更简单特别指定参数。以下是可能的代码：

\documentclass[a4paper, 12pt]{article}
\usepackage{amsmath, nccmath}
\usepackage{enumitem}
\usepackage{titlesec}
\usepackage{lipsum}

% section title format and spacing
\titleformat{\subsection}[hang]{\sffamily\Large}{Exercise \arabic{section}.\arabic{subsection}}{0pt}{}[]
\titleformat{\subsubsection}[runin]{}{(\alph{subsubsection})}{0pt}{}[]
\titlespacing{\subsubsection}{0pt}{0.5em}{0.75em}

% subsubsection indentation
\let\svsubsubsection\subsubsection
\def\subsubsection{\leftskip1em\svsubsubsection}

\begin{document}

    \setcounter{section}{1}
    \subsection{}
    \begin{enumerate}[wide = 0.6em, label=(\alph*), leftmargin=*]
      \item \lipsum[1-2]
    \item\leavevmode\vspace{-\baselineskip}\useshortskip \[ \text{some equation} \]
    \lipsum[11]
    \end{enumerate}
    \subsection{}

\end{document}