3

I am writing a paper for a class that has to include a proof. I have started out by listing what I want to prove as a theorem and then I'll go through the process of proving it. However, the code I am using below puts everything on one line and the text portion of the theorem ends up running off the page. I tried putting in "\" after the equation to put the text onto the line below it but that doesn't seem to work. Any ideas as to how I can fix this issue?

\begin{theorem}  
\[  
G(x)=\sum_{k\geq0}C_kx^k=\frac{1-\sqrt{1-4x}}{2x},\\ 
where G(x) is the generating function for the catalan number sequence.  
\]  
\end{theorem}
2
  • 1
    One can't have line breaks in a single-line displayed equation. Incidentally, why would you wish to place where G(x) is the generating function for the catalan number sequence. inside the displayed equation?
    – Mico
    Apr 30 '19 at 18:45
  • 1
    you can not have linebreaks (\\ ) in a displayed equation (\[ \]) nor can you have words of text, move where... out of the math display Apr 30 '19 at 18:59
6

First off, I wouldn't place the string where G(x) is the generating function for the catalan number sequence. inside a displayed equation. Second, one cannot have line breaks inside \[ ... \]. If you need to create a multi-line displayed equation, use a suitable environment provided by the amsmath package, such as align, gather, and multline.

enter image description here

\documentclass{article}
\usepackage{amsthm}
\newtheorem{theorem}{Theorem}
\begin{document}

\begin{theorem}  
Bla bla bla \dots
\[  
G(x)=\sum_{k\geq0}C_kx^k=\frac{1-\sqrt{1-4x}}{2x}\,,
\]  
where $G(x)$ is the generating function for the catalan number sequence.  
\end{theorem}
\end{document}
1
  • 1
    I didn't know that this was an option, I'm still new to Latex so I'm figuring most things out as I go. Thank you very much for the input, this solved the problem. Apr 30 '19 at 18:53
4

If you really wish the "where G(x) is the generating function for the catalan number sequence"-phrase to belong to the equation, which would affect the vertical spacing/the size of the vertical gap between the equation and that phrase, you can, e.g., use a gather- or a split-environment:

\documentclass{article}
\usepackage{amsmath}
\newtheorem{theorem}{Theorem}
\begin{document}
\begin{theorem}
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
\begin{gather*}
G(x)=\sum_{k\geq0}C_kx^k=\frac{1-\sqrt{1-4x}}{2x},\\
\text{where \(G(x)\) is the generating function for the catalan number sequence.}%
\end{gather*}
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
\begin{equation*}\begin{split}
&G(x)=\sum_{k\geq0}C_kx^k=\frac{1-\sqrt{1-4x}}{2x},\\
&\text{where \(G(x)\) is the generating function for the catalan number sequence.}%
\end{split}\end{equation*}
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
\end{theorem}
\end{document}

enter image description here

And in some situations a simple minipage-environment might be your friend:

\documentclass{article}
\usepackage{amsmath}
\newtheorem{theorem}{Theorem}
\begin{document}
\begin{theorem}
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
\[%
G(x)=\sum_{k\geq0}C_kx^k=\frac{1-\sqrt{1-4x}}{2x},
\text{%
  \begin{minipage}[t]{4cm}%
  where \(G(x)\) is the generating function for the catalan number sequence.%
  \end{minipage}%
}%
\]
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
\end{theorem}
\end{document}

enter image description here

Using \parshape inside minipage, you can achieve things that are even more funny:

\documentclass{article}
\usepackage{amsmath}
\newtheorem{theorem}{Theorem}
\begin{document}
\begin{theorem}
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
\[%
\boxed{%
  G(x)=\sum_{k\geq0}C_kx^k=\frac{1-\sqrt{1-4x}}{2x},
  \text{%
    \begin{minipage}[t]{1.9cm}%
    \parshape 3 0cm 1.9cm 0cm 1.9cm -5.2cm 7.1cm
    where \(G(x)\) is the generating function for the catalan number sequence.%
    \end{minipage}%
  }%
}%
\]
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
This is a theorem. This is a theorem. This is a theorem. This is a theorem. This is a theorem.
\end{theorem}
\end{document}

enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.