66 \newtheorem{defn}[prop]{Definition}         % numbered definition

    66 \newtheorem{defn}[prop]{Definition}         % numbered definition

    67 \newtheorem*{defn*}{Definition}             % unnumbered definition

    67 \newtheorem*{defn*}{Definition}             % unnumbered definition

    68 \newtheorem{question}{Question}

    68 \newtheorem{question}{Question}

    69 \newtheorem{property}{Property}

    69 \newtheorem{property}{Property}

    70 \newtheorem{axiom}{Axiom}

    70 \newtheorem{axiom}{Axiom}

    73 \newtheorem{example}[prop]{Example}

    73 \newtheorem{example}[prop]{Example}

    74 %\newenvironment{example}[1]{\textbf{Example (#1)}}{} %% how do you do numbering?

    74 %\newenvironment{example}[1]{\textbf{Example (#1)}}{} %% how do you do numbering?

    75 \newenvironment{rem}{\noindent\textsl{Remark.}}{}  % perhaps looks better than rem above?

    75 \newenvironment{rem}{\noindent\textsl{Remark.}}{}  % perhaps looks better than rem above?

    76 \numberwithin{equation}{section}

    76 \numberwithin{equation}{section}

    77 %\numberwithin{figure}{section}

    77 %\numberwithin{figure}{section}

   129 \def\bc{{\mathcal B}}

   129 \def\bc{{\mathcal B}}

   130 

   130 

   131 \newcommand{\into}{\hookrightarrow}

   131 \newcommand{\into}{\hookrightarrow}

   132 \newcommand{\onto}{\twoheadrightarrow}

   132 \newcommand{\onto}{\twoheadrightarrow}

   133 \newcommand{\iso}{\cong}

   133 \newcommand{\iso}{\cong}

   134 \newcommand{\htpy}{\simeq}

   135 \newcommand{\htpy}{\simeq}

   135 \newcommand{\actsOn}{\circlearrowright}

   136 \newcommand{\actsOn}{\circlearrowright}

   136 \newcommand{\xto}[1]{\xrightarrow{#1}}

   137 \newcommand{\xto}[1]{\xrightarrow{#1}}

   137 \newcommand{\isoto}{\xto{\iso}}

   138 \newcommand{\isoto}{\xto{\iso}}

   138 \newcommand{\quismto}{\xrightarrow[\text{q.i.}]{\iso}}

   139 \newcommand{\quismto}{\xrightarrow[\text{q.i.}]{\iso}}