diff -r 050dba5e7bdd -r a9ac20b0a0c2 preamble.tex
--- a/preamble.tex	Wed Aug 18 21:05:50 2010 -0700
+++ b/preamble.tex	Wed Aug 18 22:33:57 2010 -0700
@@ -63,6 +63,7 @@
 \newtheorem{module-axiom}{Module Axiom}
 \newenvironment{rem}{\noindent\textsl{Remark.}}{}  % perhaps looks better than rem above?
 \newtheorem{rem*}[prop]{Remark}
+\newtheorem{remark}[prop]{Remark}
 \numberwithin{equation}{section}
 %% example is defined in article_preamble.tex, for compatibility with beamer.
 
@@ -120,6 +121,7 @@
 
 
 \def\bc{{\mathcal B}}
+\def\btc{{\mathcal{BT}}}
 
 \newcommand{\into}{\hookrightarrow}
 \newcommand{\onto}{\twoheadrightarrow}