Errors on multi-line equation with brackets

Question

I am running this code for an equation that runs over into the margins:

\begin{eqnarray}
        N(t,x) &=& \inf_{u_{I+1} \in [-u_{I+1}, w_{I+1}], T_{I+1} \in \Real_+} \left\{ \inf_{u_I \in [-u_I, w_I], T_I \in \Real_+} \left\{ c(t - T_I-T_{I+1}, x + T_Iu_I+T_{I+1}u_{I+1})\\          
        &+& T_I\varphi_I(u_I) + T_{I+1}\varphi_{I+1}(u_{I+1}) \right\} \right\} \nonumber
\end{eqnarray}

Which gives:

and I keep getting myriad errors:

Extra }, or forgotten \right. &
Missing \right. inserted. &
Missing \right. inserted. &
Missing } inserted. &
Missing } inserted. ..._I) + T_{I+1}\varphi_{I+1}(u_{I+1}) \right
Extra \right. ...) + T_{I+1}\varphi_{I+1}(u_{I+1}) \right\}
Extra \right. ...1}\varphi_{I+1}(u_{I+1}) \right\} \right\}
Incomplete \ifcase; all text was ignored after line 64. \end{eqnarray}
Missing $ inserted. \end{eqnarray}
Extra alignment tab has been changed to \cr. \end{eqnarray}
Extra \or. \end{eqnarray}
Extra \or. \end{eqnarray}
Forbidden control sequence found while scanning definition of \reserved@a. \end{eqnarray}
Extra alignment tab has been changed to \cr. \end{eqnarray}
Extra \else. \end{eqnarray}
Missing $$ inserted. \end{eqnarray}
Too many columns in eqnarray environment. \end{eqnarray}
Extra \fi. \end{eqnarray}

I am not sure how to extend the double brackets across two lines.

Welcome to TSE. Please post a Minimal Working Example, instead of a code snippet. — José Carlos Santos, Nov 26 '21 at 16:26

Bernard · Answer 1 · 2021-11-27T16:43:22.290

7

Another possibility with geometry and \substack + the aligned environment:

\documentclass{article}
\usepackage{mathtools}
\usepackage{geometry}
\begin{document}
\begin{equation}%
N(t,x) = \inf_{\substack{u_{I+1} \in [-u_{I+1}, w_{I+1}],\\ T_{I+1} \in \mathbf{R}_+}} \Biggl\{ \inf_{\substack{u_I \in [-u_I, w_I],\\ T_I \in \mathbf{R}_+}} \Biggl\{\begin{aligned} c(t - T_I-T_{I+1}, x + T_Iu_I+T_{I+1}u_{I+1})\\
    {}+ T_I\varphi_I(u_I) + T_{I+1}\varphi_{I+1}(u_{I+1})
    \end{aligned} \Biggr\} \Biggr\}%
 \end{equation}


\end{document}

edited Nov 27 '21 at 16:43

answered Nov 26 '21 at 17:33

Bernard

271,350

2

+1 for the use of \substack. :-) I might be tempted to use a gathered environment for the material inside the inner curly brace, and I'd prefix {} to + T_I\varphi_I(u_I) in order to get TeX to treat + as a binary rather than as a unary operator. – Mico Nov 26 '21 at 20:15
1

@Mico: Semantically, I prefer a right alignment. For the spacing of +, you're right, and I'll fix it in a moment. I was mislead because initially, I didn't remove the \vphantom, and moved the + afterwards. – Bernard Nov 26 '21 at 20:20

José Carlos Santos · Accepted Answer · 2021-11-26T16:51:09.120

3

This will work (more or less), but your first line is too long:

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{eqnarray}
        N(t,x) &=& \inf_{u_{I+1} \in [-u_{I+1}, w_{I+1}], T_{I+1} \in \mathbf{R}_+} \left\{ \inf_{u_I \in [-u_I, w_I], T_I \in \mathbf{R}_+} \left\{ c(t - T_I-T_{I+1}, x + T_Iu_I+T_{I+1}u_{I+1})\right.\right.\\          
        &+& \left.\left.\vphantom{\inf_{u_I \in [-u_I, w_I], T_I \in \mathbf{R}_+}}T_I\varphi_I(u_I) + T_{I+1}\varphi_{I+1}(u_{I+1}) \right\} \right\} \nonumber
\end{eqnarray}
\end{document}

You shall get this:

By the way, I urge you to use align instead of eqnarray.

edited Nov 26 '21 at 16:51

answered Nov 26 '21 at 16:34

José Carlos Santos

4,803

Thank you so much! It is interesting with the \vphantom. I will use align from now on :) – Jacob Nov 26 '21 at 16:41
2

Please don't use eqnarray. – Mico Nov 26 '21 at 20:04
@Mico To whom was this written? – José Carlos Santos Nov 26 '21 at 20:05
2

@JoséCarlosSantos - To you. I know you wrote " I urge you to use align instead of eqnarray, but casual readers may well not notice this. Better not to use eqnarray at all... – Mico Nov 26 '21 at 20:12

score 3 · Answer 3 · edited Nov 27 '21 at 08:49

A variation of nice @Bernard answer with use multlined for right side of equation and \left\{ and \right\} for outer brace:

\documentclass{article}
\usepackage{mathtools}
\usepackage{geometry}
\begin{document}
    \begin{equation}%
N(t,x) = \inf_{\substack{u_{I+1} \in [-u_{I+1}, w_{I+1}],\ T_{I+1} \in \mathbf{R}+}}
            \left{ \inf{\substack{u_I \in [-u_I, w_I],\ T_I \in \mathbf{R}+}} \Biggl{\begin{multlined} 
                    c(t - T_I-T{I+1}, x + T_Iu_I+T_{I+1}u_{I+1})\
                    {}+ T_I\varphi_I(u_I) + T_{I+1}\varphi_{I+1}(u_{I+1})
                    \end{multlined} \Biggr} 
            \right}
     \end{equation}
\end{document}

Errors on multi-line equation with brackets

3 Answers3