如何强制求和的参数不被抵消

Question

现在，由于我有一个很长的底部论点，我的总结看起来是这样的：

$\sum\limits_{x \in A[1...i-1]} x$

我怎样才能使其x不被底部参数文本偏移呢？

Answer 1

您可以使用软件包\smashoperator提供的带有选项的宏来实现所需的效果。这会通知 LaTeX，应允许放在求和符号下方的材料与放在求和符号后面的材料之间有重叠。mathtools[r]

\documentclass{article}
\usepackage{mathtools} % for "\smashoperator" macro
\setlength\textwidth{3in} % just for this example
\begin{document}
No overlap on either side
\[
y = \sum_{x \in A[1,\dots,i-1]} x
\]

\bigskip
Overlap on right-hand side only
\[  % note the option "[r]" in the following line
y = \smashoperator[r]{\sum_{x \in A[1,\dots,i-1]}} x
\]

\bigskip
Overlap on both sides
\[  
y = \smashoperator{\sum_{x \in A[1,\dots,i-1]}} x
\]

\end{document}

Answer 2

看看包\mathrlap{...}中是否mathtools提供了您想要获得的内容：

\documentclass[border=3mm,preview]{standalone}
\usepackage{mathtools}

\begin{document}
\[y=\sum\limits_{\mathrlap{x \in A[1...i-1]}} x\]
\end{document}