preamble.sty

% More control for enumerate environments
\usepackage{enumitem}

% Math symbols and such
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsthm}
\usepackage{mathtools}
\usepackage{latexsym}
\usepackage{mathrsfs}
\usepackage{ wasysym }
\usepackage{bm}

% Page geometry and figures
\usepackage{graphicx}
\usepackage{afterpage}
\usepackage[nodisplayskipstretch]{setspace}
\setstretch{1.25}
\usepackage[
  left=3.25cm,
  right=3.25cm,
  bottom=4cm,
  top=4cm,
]{geometry}

% Header setup
\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhead{}
\renewcommand{\headrulewidth}{0pt}

% Colours
\usepackage[svgnames]{xcolor}
\colorlet{themecolour}{MidnightBlue}

% Quotations
\usepackage{epigraph}

% Commutative diagrams, via the WYSIWYG editor q.uiver.app
\usepackage{quiver}

% Blocks
\usepackage{framed}

% Disable paragraph indents
\newlength\normalparindent
\setlength\normalparindent{\parindent}
\usepackage{parskip}
\usepackage{etoolbox}
\newlength\normalparskip
\setlength\normalparskip{\parskip}

% The proof environment needs to be patched so that the space isn't so large,
% however, and we want to suppress parskip inside it for longer proofs
\AtBeginEnvironment{proof}{\vspace*{-0.5\normalparskip}}
\pretocmd{\proof}{
  \vspace*{\parskip}
  \setlength\parindent{\normalparindent}
  \setlength\parskip{0pt}
}{\typeout{Patched proof OK.}}{\typeout{Patching proof failed.}}
\AtEndEnvironment{proof}{\vspace*{-0.5\normalparskip}}

% There are some long examples too, so we will suppress that as well
\let\svpar\par
\edef\svparskip{\the\parskip}
\def\revertpar{\svpar\setlength\parskip{\svparskip}\let\par\svpar}
\def\noparskip{\leavevmode\setlength\parskip{0pt}%
  \setlength\parindent{\normalparindent}%
  \def\par{\svpar\let\par\revertpar}
}

% Disable footnote indents
\usepackage[
  hang,
  flushmargin,
  bottom
]{footmisc}

% Bibliography setup
\usepackage[
  backend=biber,
  style=alphabetic
]{biblatex}
\addbibresource{references.bib}

% Hyperlinks
\usepackage[colorlinks]{hyperref}
\hypersetup{
  allcolors=themecolour,
  % citecolor=blue!70!black,
  % linkcolor=,
}
\usepackage[
  capitalize,
  nameinlink
]{cleveref}

% We need the bookmark package to ensure that the bibliography links
% work in the PDF
\usepackage{bookmark}

% Setup for amsthm environments
\usepackage{amsthm}
\theoremstyle{plain}
\newtheorem{theorem}{Theorem}[section]
\newtheorem{lemma}{Lemma}[section]
\newtheorem{proposition}{Proposition}[section]
\newtheorem{corollary}{Corollary}[section]
\newtheorem{conjecture}{Conjecture}[section]
\theoremstyle{definition}
\newtheorem{definition}{Definition}[section]
\newtheorem{example}{Example}[section]
\newtheorem{remark}{Remark}[section]
\theoremstyle{remark}
\newtheorem{note}{Note}[section]

% Label equations by the sections they are in
\numberwithin{equation}{section}

\iffalse
% Change all part, chapter, section titles to normal text
\usepackage{sectsty}
\allsectionsfont{\normalfont}

% Chapter head style, taken from the unswthesis template
% This must be done after we use sectsty
\newlength{\chaprule}
\newlength{\ATchapskip}
\setlength{\chaprule}{0.4\p@}
\setlength{\ATchapskip}{10\p@}
\advance \ATchapskip by -1\chaprule
\renewcommand{\@makechapterhead}[1]{%
  \ifdim\chaprule>6\p@ \setlength{\chaprule}{6\p@}\fi
  \vspace*{\ATchapskip}%
  \noindent\rule{\textwidth}{\chaprule}\par%
  \vskip 10\p@
  {\parindent \z@ \centering \normalfont
    \ifnum \c@secnumdepth >\m@ne
    {\Large\scshape \@chapapp\space \thechapter}
    \par\nobreak
    \vskip 8\p@
    \fi
    \interlinepenalty\@M
    {\Large\normalfont #1}
    \par\nobreak
    \noindent\rule{\textwidth}{\chaprule}\par%
    \vskip\ATchapskip
}}
\renewcommand{\@makeschapterhead}[1]{%
  \ifdim\chaprule>6\p@ \setlength{\chaprule}{6\p@}\fi
  \vspace*{\ATchapskip}%
  \noindent\rule{\textwidth}{\chaprule}\par%
  \vskip 10\p@
  {\parindent \z@ \centering
    \normalfont
    \interlinepenalty\@M
    {\Large\normalfont #1}
    \par\nobreak
    \noindent\rule{\textwidth}{\chaprule}\par%
    \vskip\ATchapskip
}}

% A much simpler and different alternative with centered chapter titles
% \usepackage[center]{titlesec}
\fi