# [OS X TeX] Does {ntheorem} have a bug related to \newshadedtheorem ?

Don Green Dragon fergdc at Shaw.ca
Wed Jan 11 02:48:54 CET 2012

Hi All,

Thanks to Michael Welsh for suggesting that I look into the package {ntheorem}. So far everything seems to work, except for the command \newshadedtheorem  which works in the sense that it creates the statement of a theorem-like environment on a coloured background, but when I try to use \ref{...} or \thref{...} then the console complains that the relevant 'label' is 'undefined'. I hasten to add that the command \newframedtheorem works and does not complain about missing labels.

A reasonably simple example is

\documentclass [11pt, fleqn, leqno] {book}

\usepackage{amsmath}
\usepackage{auto-pst-pdf}
\usepackage[amsthm, thmmarks, framed, thref]{ntheorem}
\usepackage{framed}
\usepackage{pstricks}

\theoremstyle{margin}
\theoremseparator{}

\begin{document}

\chapter{On Trial}
\label{yellowguy}
\ \\This is the statement of a shaded theorem \dots. Set by \texttt{thmshaded}.

The theorem with the yellow background and optional ID
(Yellow Bird)'' is \ref{yellowguy}.

\end{document}

When the above is run the part "\ref{yellowguy}" is replaced by ?? and the console complaint is

+++++++++
LaTeX Warning: Reference yellowguy' on page 1 undefined on input line 23.

bla bla bal ...

LaTeX Warning: There were undefined references.
+++++++++

and line 23 is

(Yellow Bird)'' is \ref{yellowguy}.

Same complaint if I replace \ref by \thref.

In the {ntheorem} manual by May & Schedler, I cannot find an example where either \ref{...} or \thref{...} is applied and refers back/forward to an instance created by \newshadedtheorem.

I'm using TeXShop 2.43 still running on Snow Leopard.

Don Green Dragon
fergdc at Shaw.ca

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