# How to align the lines in a multiline equation while using the space optimally?

I have a long equation with multiple equalities where I even have to split off the first equation.

• Using 'multline' breaks the alignment of the equations
• With 'align' or 'split' I have to pick an arbitrary point in the first line to align the others to. I also cannot align within \left(...\right).

Is there a way to do it automatically? I'm looking for something that looks like this picture in the end: This is my code right now:

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\newcommand{\pot}{\ensuremath{^{p/2}}}

\begin{equation}\begin{split}
(t+\tau)\pot-C&\left(m\lor\sup_{s\leq\tau}|B_s+b|\right)^p\\
&\leq t\pot+\tau\pot-C\sup_{s\leq\tau}|B_s+b|^p\\
&\leq t\pot+\tau\pot-C\sup_{s\leq\tau}|B_s^p+b^p|\\
&\leq t\pot+\tau\pot-C\sup_{s\leq\tau}\big||B_s|^p-|b|^p\big|\\
&\leq t\pot+Cm^p+\tau\pot-CM_\tau^p\\
\end{split}\end{equation}
\end{document}

• You can align within left …\right with the \MTkillspecial command defined in § 3.6 (Paired Delimiters) of the mathtools documentation. Mar 14, 2017 at 16:42
• i assume you want just one equation number. you can use multined (requires mathtools) and use aligned for the lines after the first. Mar 14, 2017 at 17:07

How about this, with multline and aligned:

\documentclass{article}
\usepackage{mathtools, nicefrac}
\usepackage{showframe}
\renewcommand\ShowFrameLinethickness{0.3pt}
\DeclarePairedDelimiter{\abs}{\lvert}{\rvert}
\newcommand{\pot}{\ensuremath{^{p/2}}}

\begin{document}

\begin{multline}
(t+\tau)\pot-C\Bigl(m\lor\sup_{s\leq\tau}\abs{B_s+b}\Bigr)^p\\
\begin{aligned}
&\leq t\pot+\tau\pot-C\sup_{s\leq\tau}\abs{B_s+b}^p \leq t\pot+\tau\pot-C\sup_{s\leq\tau}\abs{B_s^p+b^p}\\
&\leq t\pot+\tau\pot-C\sup_{s\leq\tau}\abs[\big]{\abs{B_s}^p-\abs{b}^p}\leq t\pot+Cm^p+\tau\pot-CM_\tau^p
\end{aligned}
\end{multline}

\end{document} This is exactly what \MoveEqLeft from mathtools is for: \documentclass{article}

\usepackage{mathtools}

\begin{document}

\newcommand{\pot}{\ensuremath{^{p/2}}}

\begin{equation}
\begin{split}
\MoveEqLeft
(t+\tau)\pot-C\left(m\lor\sup_{s\leq\tau}|B_s+b|\right)^p\\
&\leq t\pot+\tau\pot-C\sup_{s\leq\tau}|B_s+b|^p\\
&\leq t\pot+\tau\pot-C\sup_{s\leq\tau}|B_s^p+b^p|\\
&\leq t\pot+\tau\pot-C\sup_{s\leq\tau}\big||B_s|^p-|b|^p\big|\\
&\leq t\po
t+Cm^p+\tau\pot-CM_\tau^p\\
\end{split}
\end{equation}

\end{document}


By default \MoveEqLeft starts the first line 2em to the left of the alignment point of the other lines. If you write \MoveEqLeft this will be changed to 5em, and so on.

• Though, I would not scale those () in the first line that much, big or Big is enough (I'm mostly allergic to left/right constructions) Mar 14, 2017 at 17:52
• @daleif Agreed - but this was to illustrate the OPs wish to be able to use \left...\right on such a line. Mar 15, 2017 at 7:15