Math & Science ⇒ amsbook | Line Spacing in 'cases' Environment

[marcdein]

I am using the cases environment in the amsbook document class. The problem I have is that the curly brace appears to be a bit too large. For example, see the code below.

Code: Select all

\[
  (q)_n=
  \begin{cases}
    {1}, & n=0,\\
    {q(q+1)\ldots (q+n-1)}, & n>0.
  \end{cases}
\]

It gives the attached result. This problem only happens when I use the amsbook class. If I use amsart, for example, everything is fine. Is there a way of fixing it?

[marcdein]

Sorted it. One needs to use

Code: Select all

\usepackage{amsmath,mathtools}
\[
\begin{dcases}
[...]
\end{dcases}
\]

Source:

http://chenfuture.wordpress.com/2011/11 ... -in-latex/

[localghost]

A complete solution in form of a self-contained code example would have been nice to have something ready to compile.

An alternative could be to typeset such case differentiations by the empheq package.

Code: Select all

\documentclass[11pt]{article}
\usepackage[T1]{fontenc}
\usepackage{empheq}   % loads »mathtools«, which in turn loads »amsmath«

\begin{document}
  \begin{empheq}[left={(q)_n=\empheqlbrace}]{alignat*=2}
    & {1}, && n=0,\\
    & {q(q+1)\ldots (q+n-1)},\quad && n>0.
  \end{empheq}
\end{document}

The package manual has more details. The cases package is another alternative and offers some other structures for customization.


Thorsten