%%  Common macros for the course CSC236H1, on the St. George Campus at
%%  the University of Toronto.
%%
%%  Copyright (c) 2009-2012 Francois Pitt <fpitt@cs.utoronto.ca>
%%  last updated at 12:38 (EST) on Wed  8 Feb 2012
%%
%%  This work may be distributed and/or modified under the conditions of
%%  the LaTeX Project Public License, either version 1.3 of this license
%%  or (at your option) any later version.
%%  The latest version of this license is in
%%      http://www.latex-project.org/lppl.txt
%%  and version 1.3 or later is part of all distributions of LaTeX
%%  version 2003/12/01 or later.
%%
%%  This work has the LPPL maintenance status "author-maintained".
%%
%%  The Current Maintainer of this work is
%%  Francois Pitt <fpitt@cs.utoronto.ca>.
%%
%%  This work consists of the file macros-236.tex.

% Trick so that math symbols are bold when text is.
\let\seiresfb\bfseries\def\bfseries{\boldmath\seiresfb}
\let\seiresdm\mdseries\def\mdseries{\unboldmath\seiresdm}

% Centered version of \llap and \rlap.
\newcommand*{\clap}[1]{\hbox to 0pt{\hss#1\hss}}

% Spacing macros with default argument.
\newcommand*{\vstretch}[1][1]{\vspace*{\stretch{#1}}}
\newcommand*{\hstretch}[1][1]{\hspace*{\stretch{#1}}}

% General fonts and characters.
\let\altemph\textsl  % alternate way to emphasize
\let\strong\textbf  % strong emphasis
\let\code\texttt  % code fragments
\let\const\textsf  % constants
\let\var\textsl  % multi-letter variables (or constants)
\newcommand*{\txtbksl} {\symbol{"5C}}% \
\newcommand*{\txtcaret}{\symbol{"5E}}% ^
\newcommand*{\txtunder}{\symbol{"5F}}% _
\newcommand*{\txtlcurl}{\symbol{"7B}}% {
\newcommand*{\txtrcurl}{\symbol{"7D}}% }
\newcommand*{\txttilde}{\symbol{"7E}}% ~
\newcommand*{\N}{\ensuremath{\mathbb{N}}}  % requires amssymb
\newcommand*{\Z}{\ensuremath{\mathbb{Z}}}  % requires amssymb
\newcommand*{\Q}{\ensuremath{\mathbb{Q}}}  % requires amssymb
\newcommand*{\R}{\ensuremath{\mathbb{R}}}  % requires amssymb
\newcommand*{\bigOh}{\mathcal{O}}
\newcommand*{\onehalf}{\ensuremath{{}^1\!\!/\!_2}}

% Abbreviations of latin phrases.
\let\latinabb\emph  % abbreviations of latin phrases
\newcommand*{\ie}{\latinabb{i.e.}}
\newcommand*{\eg}{\latinabb{e.g.}}
\newcommand*{\etc}{\latinabb{etc}}
\newcommand*{\vs}{\latinabb{vs}}

% General math macros.
\newcommand*{\comp}[1]{\overline{#1}}  % set complement
\newcommand*{\emptystr}{\varepsilon}  % empty string
\newcommand*{\lequiv}{\mathrel{\ \Longleftrightarrow\ }}  % equivalence
\newcommand*{\lxor}{\mathbin\oplus}  % exclusive or
\newcommand*{\cat}{\cdot}  % string concatenation
\newcommand*{\invisible}[1]{\mathrel{\hphantom{#1}}}
% Floors and ceilings, with optional size-changing command, e.g.,
% \floor[\Big]{x/2} generates '\Big\lfloor{x/2}\Big\rfloor'.
\newcommand*{\floor}[2][]{{#1\lfloor}{#2}{#1\rfloor}}
\newcommand*{\ceil}[2][]{{#1\lceil}{#2}{#1\rceil}}
\newcommand*{\lcm}{\operatorname{lcm}}  % requires amsmath
\newcommand*{\len}{\operatorname{len}}  % requires amsmath
\newcommand*{\size}{\operatorname{size}}  % requires amsmath

% Redefined symbols from amssymb.
\renewcommand*{\emptyset}{\varnothing}  % rounder than default
\let\bigiff\iff
\renewcommand*{\iff}{\mathrel{\Leftrightarrow}}  % smaller than default
\let\bigimplies\implies
\renewcommand*{\implies}{\mathrel{\Rightarrow}}  % smaller than default
\renewcommand*{\ge}{\geqslant}  % with slanted line under the > sign
\renewcommand*{\le}{\leqslant}  % with slanted line under the < sign

% For algorithms, in pseudo-code.
\let\kw\textbf  % keywords
\let\proc\textsc  % function names
\newcommand*{\True}{\const{True}}
\newcommand*{\False}{\const{False}}
\newcommand*{\None}{\const{None}}
\newcommand*{\cmod}{\mathbin{\%}}

% Like {itemize} but using less vertical space.
\newenvironment*{points}
 {\ifvmode\else\unskip\par\fi\begin{list}{$\bullet$}
   {\setlength{\topsep}{.25ex plus .125ex minus .1825ex}
    \setlength{\itemsep}{\topsep}\setlength{\parsep}{0ex}
    \setlength{\leftmargin}{1.75em}\setlength{\labelsep}{.5em}
    \setlength{\labelwidth}{1.75em}}\ignorespaces}
 {\ifvmode\else\unskip\fi\end{list}\ignorespaces}

% Checkboxes and checklists.
\newcommand*{\cbox}[1]{{\fboxrule.125ex\fboxsep0ex
    \framebox[2.75ex]{\rule[-.75ex]{0ex}{2.75ex}\smash{#1}}}}
\newcommand*{\cmark}{\raisebox{.0625ex}{$\surd$\kern.125ex}}
\newcommand*{\xmark}{\raisebox{-.1875ex}{\kern.0625ex{X}}}
\newcommand*{\checkbox}{{\sf\cbox{}}}
\newcommand*{\checkedbox}{{\sf\cbox{\cmark}}}
\newcommand*{\markedbox}{{\sf\cbox{\xmark}}}
\newenvironment{checklist}{\begin{list}{\checkbox}{}}{\end{list}}
\newcommand*{\checkeditem}{\item[\checkedbox]}
\newcommand*{\markeditem}{\item[\markedbox]}

% Proof-related environments and macros.
\newcommand*{\just}{{\quad\#\ }}  % justification for a proof step
\newenvironment*{pindent}
   {\begin{list}{}
       {\topsep 0pt
        \partopsep 0pt
        \itemsep 0pt
        \parsep 0pt
        \parskip 0pt}\item\relax}
   {\unskip\end{list}\ignorespaces}

% CFGs.
\newcommand*{\yields}{\mathrel{\,::=\,}}
\newcommand*{\phantyields}{\mathrel{\hphantom{\yields}}}
\newcommand*{\baror}{\mathbin{\,|\,}}
\newcommand*{\gvar}[1]{\ensuremath{\langle\mathrm{#1}\rangle}}
\newcommand*{\term}[1]{\ensuremath{\mathbin{\mathsf{#1}}}}

% 236-specific.
\newcommand*{\LI}{\textsl{LI}}  % for loop invariants