3

I don't know what to search, so I'm adding a picture of what I want to do. Basically, I want to write multiple set constraints on the right hand side (see below). How do I accomplish this in latex?

enter image description here

yoshi
  • 141

2 Answers2

3

Something of this type?

\documentclass[a4paper,12pt]{article}
\usepackage{amsmath,amssymb}
\begin{document}
\[
U=\left\{ (u,v) \;\middle\vert\;
   \begin{array}{@{}l@{}}
   u, v\colon \mathbb{R}^d\to[0,\infty) \\ 
   \text{bla bla bla}\\
   u+v<7 
   \end{array}
\right\} 
\]
\end{document}
Mico
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Sebastiano
  • 54,118
  • 2
    +1. I've taken the liberty of streamlining your code slightly, e.g., by using \;\middle\vert\;. Feel free to revert. – Mico Jul 17 '19 at 17:32
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    @Mico You are ALWAYS welcome into my heart. Very best user can take the liberty to edit my code. Grazieeeeeeeeeeeeeeeeeeeeeeeeeeeee. – Sebastiano Jul 17 '19 at 18:43
  • can you explain the {@{}l@{}} symbols? – yoshi Jul 17 '19 at 21:42
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    @yoshi the concept is not simple. It only serves to correctly align the array to have the three relationships aligned to the left: see for example this link https://tex.stackexchange.com/questions/207457/question-about-used-in-array-environment. See also the another answer of great user Bernard. – Sebastiano Jul 17 '19 at 21:47
2

Another solution, base on \DeclarePairedDelimiterX from mathtools and``xparse` for a natural syntax (I mean, close to what one writes by hand):

\documentclass{article}

\usepackage{amssymb}
\usepackage{mathtools}
\usepackage{xparse} 

\DeclarePairedDelimiterX{\Set}[1]\{\}{\setargs{#1}}
\NewDocumentCommand{\setargs}{>{\SplitArgument{1}{|}}m}
{\setargsaux#1}
\NewDocumentCommand{\setargsaux}{mm}
{\IfNoValueTF{#2}{#1}{\nonscript\,#1\nonscript\;\delimsize\vert\allowbreak \nonscript\:\mathopen{}#2\nonscript\,}}

\begin{document}

\[ \Set*{(u, v) | \begin{array}{@{}l@{}}
        u, v: \mathbb{R}^d ―――→ [0,∞)\\[-0.5ex]
        \text{upper semi-continuous} \\[-0.5ex]
        u + v < 7
                        \end{array}} \]%

  \end{document}

enter image description here

Bernard
  • 271,350