[Tex/LaTex] Linebreak inside ‘align’

alignline-breakingmath-mode

I tried to linebreak inside math mode which did not work. So searching for that led me to try using 'align' instead. So I'm trying to break a line inside align with the following code:

\documentclass{article}
\usepackage{amsmath}

\begin{document}


\begin{align}
R = \left\{(S_1,S_1), (S_1,S_4), (S_4,S_4), (S_4,S_1), (S_2,S_2), (S_2,S_3),    (S_3,S_3), (S_3,S_2), (S_0,S_0), \\
(S_0, S_5), (S_5,S_5) , (S_5,S_0)\right\}
\end{align}

\end{document}

I get the error message : Extra }, or forgotten \right. \end{align} which I don't understand since I do have an opening and closing curly bracket?

Anyhow, the above does break the line in some way but it looks really ugly, and aligned to the right for some reason. Could someone show me how I could align the set I'm trying to write out, nicely on two lines?

Best Answer

In order to fix that, you will have to give the \left\{ its counterpart which would be \right. on the same line. The second line would need a \left. ... \right\} .

As you do not need auto-sized brackets here, I would leave it all away.

Here is your example and my version:

% arara: pdflatex

\documentclass{article}
\usepackage{mathtools}

\begin{document}
    \begin{align}
    R = \left\{(S_1,S_1), (S_1,S_4), (S_4,S_4), (S_4,S_1), (S_2,S_2), (S_2,S_3), (S_3,S_3), (S_3,S_2), (S_0,S_0),\right. \\
    \left.(S_0, S_5), (S_5,S_5) , (S_5,S_0)\right\}
    \end{align}
    \begin{equation}    
    \begin{split}
        R = \{(S_1,S_1), (S_1,S_4), (S_4,S_4), (S_4,S_1), (S_2,S_2), (S_2,S_3), (S_3,S_3),\\ (S_3,S_2), (S_0,S_0), (S_0, S_5), (S_5,S_5) , (S_5,S_0)\}
    \end{split} 
    \end{equation}
\end{document}

And here is a screen-shot of the second version (as the first version exceeds all possible limits...)

enter image description here

Related Solutions

[Tex/LaTex] Using \gather and \align together

[Note: the improvement below, actually does not work.]

~~[Note: there is an important improvement to this code below.]~~

The closest I can get to a solution is

\documentclass[10pt,a4paper]{article}

\usepackage{amsmath,amsthm,mathtools}

\begin{document}
\begin{proof}
  \begin{align*}
    15 &= 5+4+3+2+1 = \sum_{i=1}^5 i \\
    120&=5\cdot4\cdot3\cdot2\cdot1 = 5! \\
    \shortintertext{
      \[ e^{\pi i} + 1 = 0 \]
      \[ x^n + y^n = z^n \]
    } 
    27 &= 3^3 \qedhere
  \end{align*}
\end{proof}
\end{document}

which gives as result Centered equation in align

and actually the spacing is quite nice, I think.

Failing important edit

I think the below code is nicer, and even gives better results.

\documentclass[10pt,a4paper]{article} \usepackage{amsmath,amsthm,mathtools} \begin{document} \begin{proof} \begin{align*} 15 &= 5+4+3+2+1 = \sum_{i=1}^5 i \\ 120&=5\cdot4\cdot3\cdot2\cdot1 = 5! \\ \begin{gathered} e^{\pi i} + 1 = 0 \\ x^n + y^n = z^n \end{gathered} 27 &= 3^3 \qedhere \end{align*} \end{proof} \end{document}

~~Credits go to barbara beeton (please vote up her comment on her own answer).~~

[Tex/LaTex] Errors when trying to define a custom align environment

I'm not sure why but you can't use \begin{align} and \end{align} in the definition of a new environment; you have to use the "lower-level" macros \align and \endalign instead. Edit: as pointed by alexwlchan in his comment, you can find more details about that in section 6 of Technical notes on the amsmath package.

Here I've used the equivalent of an align* environment (see Herbert's answer to Define a custom align, and align* environment).

Note that you will get an error if you try to reset your grammarcounter at each chapter in the article class, because the latter doesn't have chapters; \section is the most high-level sectioning command in the article class. Did you mean

\numberwithin{grammarcounter}{section}

instead?

enter image description here

\documentclass{article}

\usepackage{amsmath}

\newcounter{grammarcounter}[section]

\makeatletter
\newenvironment{grammar}
{%
  \refstepcounter{grammarcounter}
  \start@align\@ne\st@rredtrue\m@ne
  \tag{$\Gamma_{\thegrammarcounter}$}
}{%
  \endalign
}
\makeatother
 
\begin{document}

\section{Foo}

\begin{grammar}
\label{gr:label}
E &::= E + E \\
E &::= a     \\
E &::= b     
\end{grammar}

\begin{grammar}
\label{gr:label2}
E &::= E + E \\
E &::= a     \\
E &::= b     
\end{grammar}

\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Using \gather and \align together

Failing important edit

[Tex/LaTex] Errors when trying to define a custom align environment

Related Question