\usepackage{xcolor}

\usepackage{fontspec}

\usepackage[sc]{mathpazo}

\setmainfont[Ligatures=TeX]{Palatino Linotype}

\usepackage{amssymb}

\usepackage{amsmath}

\usepackage{menukeys}

\@ifpackageloaded{hyperref}{}{\usepackage{hyperref}}

\definecolor{darkblue}{rgb}{0,0,0.6}

\hypersetup{colorlinks=true}

\hypersetup{linkcolor=darkblue}

\hypersetup{urlcolor=darkblue}

\ifx\foobar\undefined \else

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\fi

\definecolor{codegray}{gray}{0.9}

\newcommand\grid[1]{%

\begin{tikzpicture}[baseline=(char.base)]

  \path[use as bounding box]

    (0,0) rectangle (1em,1em);

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\newcommand\gridraiseamount{0.12em}

\makeatletter

\newcommand\Grid[1]{%

  \@tfor\z:=#1\do{\grid{\z}}}

\makeatother	

\makeatletter

\def\fnote{\gdef\@thefnmark{}\@footnotetext}

\makeatother

\newcommand{\HEADER}{{\bf Please submit your solutions to the

email address 7ccsmsen at gmail dot com. Please submit only one

homework per email. Work in pairs and submit a \underline{single}

solution! CC the email to your partner. Please also submit only

ASCII text or PDFs (no .docs etc). Every solution should be preceded by the

corresponding question, like:

\begin{center}

\begin{tabular}{ll}

Q$n$: & \ldots a difficult question from me\ldots\\

A:    & \ldots an answer from you \ldots\\

Q$n+1$ & \ldots another difficult question\ldots\\

A:     & \ldots another brilliant answer from you\ldots

\end{tabular}

\end{center}

\noindent Solutions will only be accepted until

20th December!}} 

\newcommand{\POSTSCRIPT}{

{\bf (Optional)} This question is for you to provide 

regular feedback to me, for example 

what were the most interesting, least interesting, or confusing parts in this lecture?

Is there anything you like to have improved or explained in the handouts?

Please feel free to share any other questions or concerns.}