%
% Case 2 (x < 0): derp.
%
+\ifx\havemjoproofbycases\undefined
+\def\havemjoproofbycases{1}
-% Used below to define pcases.
-\usepackage{enumitem}
+
+% Used below to define pcases. The ``loadonly'' parameter prevents
+% a very bad interaction with the beamer document class.
+\usepackage[loadonly]{enumitem}
+
+% Needed to perform division in the definition of \singleblskip.
+\usepackage{calc}
+
+% A \baselineskip without the \baselinestretch scaling factor. Even
+% though \baselinestretch defaults to 1.0, it doesn't really have that
+% value. Thus to avoid division by zero, we need to do the ``is this
+% thing empty?'' hack.
+%
+% If we use \baselineskip instead of \singleblskip in our list, things
+% get real ugly when the text is e.g. double-spaced.
+%
+\newlength{\singleblskip}
+\setlength{\singleblskip}{
+ \baselineskip/\real{
+ \if\relax\detokenize{\baselinestretch}\relax
+ \baselinestretch%
+ \else
+ 1%
+ \fi}
+}
% Using the enumitem package, we define a new type of list, called
% ``pcases'' (proof by cases). Each case has a label with an arabic
% another.
\newlist{pcases}{enumerate}{1}
\setlist[pcases]{
- label=\textbf{Case~\arabic*}~(\protect\thiscase)\textbf{:},
+ label=\textit{Case~\arabic*}:~\protect\thiscase\textit{.},
ref=\arabic*,
align=left,
- leftmargin=\parindent}
+ listparindent=\parindent,
+ parsep=\parskip,
+ itemsep=\singleblskip}
% The optional argument here gets stuffed into the \thiscase macro, to
% be called by pcases when it creates this list item. The \hfill is a
% so we consume the rest of the line instead.
\newcommand{\case}[1][]{
\def\thiscase{#1}%
- \item \hfill\par
+ \item \hfill\par\vspace{\singleblskip}
}
+
+
+\fi