# How Can I Align Multiple Lines on a Right Bracket?

I am trying to align 2 equations on a right bracket enviroment. Below is my code and enviroment for Right Cases/Brackets

\documentclass{report}

\newenvironment{rcases}
{\left.\begin{aligned}}
{\end{aligned}\right\rbrace}

\begin{document}

\begin{align*}
\begin{rcases}
+:\, & \mathbb{N} \times \mathbb{N} \longmapsto \mathbb{N} \\
& (x, y) \longmapsto x + y
\end{rcases}
&& + \subseteq \mathbb{N} \times \mathbb{N} \\
&& + = \{ (x, y) \,|\, x, y \in \mathbb{N} \} \subseteq \mathbb{N} \times \mathbb{N}
\end{align*}

\end{document}


I am trying to get

&& + \subseteq \mathbb{N} \times \mathbb{N} \\
&& + = \{ (x, y) \,|\, x, y \in \mathbb{N} \} \subseteq


on the same line or to the same level on the right bracket.

Can someone help me with it?

What happens is that the part

& + \subseteq \mathbb{N} \times \mathbb{N}
\\
& + = \{ (x, y) \,|\, x, y \in \mathbb{N} \} \subseteq


Is treated by align* as two different lines. What you want align* to do is treat it as one symbol, which you can do by nesting aligned inside align* environment. You can think of it as illustrated here

\documentclass{report}

\usepackage{amsmath}
\usepackage{amssymb, amsfonts}
\newenvironment{rcases}
{\left.\begin{aligned}}
{\end{aligned}\right\rbrace}

\begin{document}

\begin{align*}
\begin{rcases}
+:\, & \mathbb{N} \times \mathbb{N} \longmapsto \mathbb{N}
\\
& (x, y) \longmapsto x + y
\end{rcases}
\begin{aligned}
& + \subseteq \mathbb{N} \times \mathbb{N}
\\
& + = \{ (x, y) \,|\, x, y \in \mathbb{N} \} \subseteq
\end{aligned}
\end{align*}

\end{document}

• But I need those 2 things aligned left, not right – Arszilla Sep 20 '18 at 20:37
• Amazing. Thank you. Mind explaining what you did here so I can understand it better (As I am a newbie in TeX) – Arszilla Sep 20 '18 at 20:44

The rcases environment is already defined by mathtools (which extends amsmath). I propose to use the alignatenvironment, which gives you full control on the spacing between the two groups of alignment:

\documentclass{report}

\usepackage{mathtools}
\usepackage{amssymb}

\begin{document}

\begin{alignat*}{2}
& \begin{rcases}
\begin{aligned}
+:\, & \mathbb{N} \times \mathbb{N} \longmapsto \mathbb{N}
\\
& (x, y) \longmapsto x + y \strut
\end{aligned}
\end{rcases}