我正在寻找一个可以对齐方程式的环境，如以下示例所示（摘自 Dunford & Schwartz 的书）
我的意思是主方程内容居中且可变，量词推到右边。请注意，与单个方程对齐并不能给出我想要的结果，因为它$f\in F$没有完全推到右边并且积分没有居中。
嗯，有什么想法吗？
谢谢。
答案1
您可以使用 来实现flalign，但我认为这种风格很糟糕。我建议使用其他两种方法，我更喜欢最后一种。
\documentclass[a4paper,12pt]{article}
\usepackage{amsmath}
\begin{document}
\noindent % just for emulating the original
conditions guaranteeing that
\begin{flalign*}
&& \int_{0}^{1} f(s)\phi_{n}(s)\,ds \to 0, &&& f\in F.
\end{flalign*}
Where the functions $f$ and $\phi_{n}$ are taken to be
in certain preassigned blah blah blah blah blah
\bigskip
\noindent % just for emulating the original
conditions guaranteeing that
\begin{equation*}
\int_{0}^{1} f(s)\phi_{n}(s)\,ds \to 0,\qquad f\in F,
\end{equation*}
where the functions $f$ and $\phi_{n}$ are taken to be
in certain preassigned blah blah blah blah blah
\bigskip
\noindent % just for emulating the original
conditions guaranteeing that, for $f\in F$,
\begin{equation*}
\int_{0}^{1} f(s)\phi_{n}(s)\,ds \to 0,
\end{equation*}
where the functions $f$ and $\phi_{n}$ are taken to be
in certain preassigned blah blah blah blah blah
\end{document}
我修正了明显的拼写错误（解析显然应该德斯），并在最后两个例子中删除了“where”之前语法错误的句号。
通过使条件具有零宽度，可以使主公式居中（但这不适用于更宽的主公式）。
\documentclass[a4paper,12pt]{article}
\usepackage{amsmath,mathtools}
\begin{document}
\noindent % just for emulating the original
conditions guaranteeing that
\begin{flalign*}
&& \int_{0}^{1} f(s)\phi_{n}(s)\,ds \to 0{,} &&& \mathllap{f\in F}.
\end{flalign*}
Where the functions $f$ and $\phi_{n}$ are taken to be
in certain preassigned blah blah blah blah blah
\bigskip
\noindent % just for emulating the original
conditions guaranteeing that
\begin{equation*}
\int_{0}^{1} f(s)\phi_{n}(s)\,ds \to 0{,}\mathrlap{\qquad f\in F,}
\end{equation*}
where the functions $f$ and $\phi_{n}$ are taken to be
in certain preassigned blah blah blah blah blah
\bigskip
\noindent % just for emulating the original
conditions guaranteeing that, for $f\in F$,
\begin{equation*}
\int_{0}^{1} f(s)\phi_{n}(s)\,ds \to 0,
\end{equation*}
where the functions $f$ and $\phi_{n}$ are taken to be
in certain preassigned blah blah blah blah blah
\end{document}
答案2
这些变体允许将主要方程置于边距的中心。
最后一种解决方案是，对于连续方程式，其量词位于右边距，让所有量词从页面上的同一位置开始，最宽的量词恰好位于右边距：
\documentclass[12pt]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[lf]{MinionPro}
\usepackage[showframe]{geometry}
\usepackage{mathtools, eqparbox}
\begin{document}
\noindent
conditions guaranteeing that
\begin{align*}
& & ∫_0¹f(s)\phi_n(s)\,d\mkern1mu s & \to 0 & & \mathrlap{f ∈ F. }
\end{align*}
\begin{align*}
& & ∫_0¹f(s)g(s)\phi_n(s)\,d\mkern1mu s & \to 0 & & \mathrlap{f, g ∈ F. }
\end{align*}
where the functions $ f, g $ and $ \{\phi_n\} $ are taken to be in certain preassigned
\vskip 5ex
\noindent
conditions guaranteeing that
\begin{flalign*}
& & ∫_0¹f(s)\phi_n(s)\,d\mkern1mu s &\to 0 && \mathllap{f ∈ F. }
\end{flalign*}
\begin{flalign*}
& & ∫_0¹f(s)g(s)\phi_n(s)\,d\mkern1mu s &\to 0 & \mathllap{f, g ∈ F. }&
\end{flalign*}
where the functions $ f, g $ and $ \{\phi_n\} $ are taken to be in certain preassigned
\vskip 5ex
\noindent
conditions guaranteeing that
\begin{flalign*}
& & ∫_0¹f(s)\phi_n(s)\,d\mkern1mu s &\to 0 && \llap{\eqparbox{Q}{$ f ∈ F. $} }
\end{flalign*}
\begin{flalign*}
& & ∫_0¹f(s)g(s)\phi_n(s)\,d\mkern1mu s &\to 0 & \llap{\eqparbox{Q}{$ f, g ∈ F. $ }}&
\end{flalign*}
where the functions $ f, g $ and $ \{\phi_n\} $ are taken to be in certain preassigned
\end{document}
