将拆分环境左对齐

Question

这是我的代码

\begin{equation*}
\Pi_1(X)=\Bigg\langle a_i, b_i, g_j, h\Bigg|
\begin{split}
&\prod_{i=1}^g[a_i,b_i]\prod_{j=1}^kq_j=1, g_0^bh=1,\\
&g_i^{\alpha_i}h^{\beta_i}=1, [h,q_j]=[h,a_i]=[h,b_i]=1 \\
\end{split}\Bigg\rangle.
\end{equation*}

这就是我得到的 我怎样才能消除所有间距？

Answer 1

您在找这个吗？

\documentclass[12pt,a4paper]{article}
\usepackage{mathtools}
\begin{document}
    \begin{equation*}
        \Pi_1(X)=\Bigg\langle a_i, b_i, g_j, h\Bigg|%
        \begin{multlined}
            \prod_{i=1}^g[a_i,b_i]\prod_{j=1}^kq_j=1, g_0^bh=1,\\
            g_i^{\alpha_i}h^{\beta_i}=1, [h,q_j]=[h,a_i]=[h,b_i]=1 \\
        \end{multlined}\Bigg\rangle.
    \end{equation*}
\end{document}

Answer 2

使用aligned而不是split：

\documentclass{article}

\usepackage{amsmath}

\begin{document}

\[
  \Pi_1(X) = \Bigg\langle a_i, b_i, g_j, h \Bigg|
  \begin{split}
    & \prod_{i = 1}^g[a_i,b_i] \prod_{j = 1}^k q_j = 1, g_0^b h = 1,  \\
    & g_i^{\alpha_i} h^{\beta_i} = 1, [h,q_j] = [h,a_i] = [h,b_i] = 1
  \end{split}
  \Bigg\rangle.
\]

\[
  \Pi_1(X) = \Biggl\langle a_i, b_i, g_j, h \Biggm|
  \begin{aligned}
    & \prod_{i = 1}^g[a_i,b_i] \prod_{j = 1}^k q_j = 1, g_0^b h = 1,  \\
    & g_i^{\alpha_i} h^{\beta_i} = 1, [h,q_j] = [h,a_i] = [h,b_i] = 1
  \end{aligned}
  \Biggr\rangle.
\]

\end{document}