\hypersetup{urlcolor=blue, linkcolor=blue} % change url color to blue
\hypersetup{bookmarksopen=true} % enable sidebar bookmarks in PDF mode based on \[sub]section labels and expand by default
\renewcommand{\arraystretch}{1.2} % I feel like most arrays/tables/etc in LaTeX could use a bit more room between cells
+\usepackage{framed,color}
% My commands
\newcommand{\sups}[1]{\ensuremath{^{\textrm{#1}}}}
\newcommand{\abs}[1]{\left|#1\right|}
\newcommand{\surreal}[2]{\ensuremath{\left\langle #1 \vert #2 \right\rangle}}
\newcommand{\similar}[0]{\thicksim}
+\newcommand{\set}[1]{\ensuremath{\{\,#1\,\}}}
\newcommand{\horzline}[1][350]{\begin{center} \line(1,0){#1} \end{center}}
\renewcommand\maketitle{
\thispagestyle{plain}
\subsection{Notation}
-A surreal number $X$ consisting of left set $X_L$ and right set $X_R$ is
+A surreal number $x$ consisting of left set $X_L$ and right set $X_R$ is
represented as \surreal{X_L}{X_R}. The void set, as Knuth named it, is
represented by leaving the appropriate left or right set empty, as in
\surreal{}{}, the first surreal number defined.