I am working with the ntheorem package and a while back customized it. I would like my propositions, theorems, corollaries, and lemmas to be numbered as followed (for Chapter 1 - all of them regardless of which of the four they are): 1.1, 1.2, 1.3 etc. Then, in Chapter 2 (again regardless of chiwh of the four they are): 2.1, 2.2, 2.3 etc.
Here is my MWE. For some reason when I take my entire document and attempt to make a MWE, it does not compile. I get an error message:
undefined control sequence \begin{prop}
However, my entire document does.
\documentclass[12pt]{report}
\usepackage{amsmath,amscd,amsbsy,array,color,pxfonts,latexsym}
\usepackage{mathtools}
\usepackage[amsmath,framed,thmmarks]{ntheorem}
\usepackage{amssymb}
\usepackage[thmmarks]{ntheorem}
\newtheorem{Theorem}{Theorem}
\theoremclass{Theorem}
\theoremstyle{break}
\theoreminframepreskip{0pt}
\theoreminframepostskip{0pt}
\theoremframepreskip{1cm}
\theoremframepostskip{1cm}
\theoremstyle{break}
\def\theoremframecommand{%
\psshadowbox[fillstyle=solid,fillcolor=cyan,linecolor=black]}
\newshadedtheorem{them}{Theorem}[section]
\theoremclass{Theorem}
\theoremstyle{break}
\theoreminframepreskip{0pt}
\theoreminframepostskip{0pt}
\theoremframepreskip{1cm}
\theoremframepostskip{1cm}
\theoremstyle{break}
\def\theoremframecommand{%
\psshadowbox[fillstyle=solid,fillcolor=gray,linecolor=black]}
\newshadedtheorem{prop}{Proposition}[section]
\theoremstyle{break}
\theoremsymbol{\ensuremath{\heartsuit}}
\theoremindent0.5cm
\theoremnumbering{arabic}
\newtheorem{lema}{Lemma}
\theoremindent0cm
\theoremsymbol{\ensuremath{\spadesuit}}
\theoremnumbering{arabic}
\newtheorem{coro}{Corollary}[section]
\title{MWE}
\author{Michael Dykes}
\begin{document}
\maketitle
\chapter{Analysis}
\section{The Set of Natural Numbers}
\begin{prop}[Cancellation Law for Addition]
If $x+z=y+z$ for some $x,y,z \in \mathbb{N}$, then $x=y$.
\end{prop}
\begin{lema}
For $x,y \in \mathbb{N}$ and $y \ne 0$, we have that $x+y \ne x$.
\end{lema}
\begin{them}[Trichotomy Law for Addition]
For any $x,y \in \mathbb{N}$, \textbf{exactly one} of the following three statements is true:
\begin{enumerate}[label=\roman*.]
\item $x=y$;
\item $x=y+z$ for some $z \in \mathbb{N}^*$;
\item $y=x+z$ for some $z \in \mathbb{N}*$.
\end{enumerate}
\end{them}
\end{document}
Thanks so much!
\newshadedtheorem{them}{Theorem}[section]
and\newtheorem{coro}{Corollary}[section]
? This makes the section number, not the chapter, the common prefix. Please advise.