线扩展并与下一列混合

Question

一条线展开并进入下一列。我不知道如何纠正这个问题。图片和代码已附加，如果有人能帮忙请提供。

\begin{multline*}\tag{21}
NUP_S =1- \text{probability of  successfully finishing  an  SU  service}\\
= 1 - \frac{\lambda_S(1-P^{BL}_S)(1-P^{FT}_S)}{\lambda_S}\\
= P^{BL}_S + P^{FT}_S + P^{BL}_S  P^{FT}_S\\
NUP_S= P^{BL}_S + P^{FT}_S - P^{BL}_S  P^{FT}_S\\
\end{multline*}

Answer 1

您可以使用linegoal包来设置 parbox 宽度，以便它结束于列的右侧（需要两次编译）：

\documentclass[twocolumn]{article}
\usepackage[showframe]{geometry}%
\usepackage{mathtools}
\usepackage{linegoal}
\usepackage{lipsum}

\begin{document}

\begin{equation*}\tag{21}
\begin{aligned}
NUP_S & =1- \rlap{\parbox[t]{\linegoal}{probability of successfully finishing an SU service}}\\
 & = 1 - \frac{\lambda_S(1-P^{BL}_S)(1-P^{FT}_S)}{\lambda_S}\\
 & = P^{BL}_S + P^{FT}_S + P^{BL}_S P^{FT}_S\\
NUP_S & = P^{BL}_S + P^{FT}_S - P^{BL}_S P^{FT}_S\\
\end{aligned}
\end{equation*}

\lipsum

\end{document}