\usepackage[english]{babel}
\usepackage{pslatex}
\usepackage{graphicx}
\usepackage{tikz}
\usepackage{xcolor}
\usepackage{amsmath}
\usepackage{amssymb}

%%%%% listings %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage{listings}
\lstset{
  language=Matlab,
  basicstyle=\ttfamily\footnotesize,
  numbers=left,
  numberstyle=\tiny,
  title=\lstname,
  showstringspaces=false,
  commentstyle=\itshape\color{darkgray},
  breaklines=true,
  breakautoindent=true,
  % columns=flexible,
  frame=single,
  xleftmargin=1.5em,
  xrightmargin=1em,
  aboveskip=10pt
}

%%%%% page style %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage[left=20mm,right=20mm,top=25mm,bottom=19mm,headsep=2ex,headheight=3ex,footskip=3.5ex]{geometry}
\pagestyle{headandfoot}
\ifprintanswers
\newcommand{\stitle}{Solutions}
\else
\newcommand{\stitle}{}
\fi
\header{{\bfseries\large \exercisenum. \exercisetopic}}{{\bfseries\large\stitle}}{{\bfseries\large\exercisedate}}
\firstpagefooter{Prof. Dr. Jan Benda}{}{jan.benda@uni-tuebingen.de}
\runningfooter{}{\thepage}{}

\shadedsolutions
\definecolor{SolutionColor}{gray}{0.9}

\setlength{\baselineskip}{15pt}
\setlength{\parindent}{0.0cm}
\setlength{\parskip}{0.3cm}

\usepackage{multicol}

%%%%% units %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage[mediumspace,mediumqspace,Gray,squaren]{SIunits}      % \ohm, \micro

%%%%% new commands %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\newcommand{\cin}[1]{[{\rm #1}]_{\text{in}}}
\newcommand{\cout}[1]{[{\rm #1}]_{\text{out}}}
\newcommand{\units}[1]{\text{#1}}
\newcommand{\K}{\text{K$^+$}}
\newcommand{\Na}{\text{Na$^+$}}
\newcommand{\Cl}{\text{Cl$^-$}}
\newcommand{\Ca}{\text{Ca$^{2+}$}}
\newcommand{\water}{$\text{H}_2\text{O}$}

\usepackage{dsfont}
\newcommand{\naZ}{\mathds{N}}
\newcommand{\gaZ}{\mathds{Z}}
\newcommand{\raZ}{\mathds{Q}}
\newcommand{\reZ}{\mathds{R}}
\newcommand{\reZp}{\mathds{R^+}}
\newcommand{\reZpN}{\mathds{R^+_0}}
\newcommand{\koZ}{\mathds{C}}
\newcommand{\RT}{{\rm Re\!\ }}
\newcommand{\IT}{{\rm Im\!\ }}
\newcommand{\arccot}{{\rm arccot}}
\newcommand{\sgn}{{\rm sgn}}
\newcommand{\im}{{\rm i}}
\newcommand{\drv}{\mathrm{d}}
\newcommand{\divis}[2]{$^{#1}\!\!/\!_{#2}$}
\newcommand{\vect}[2]{\left( \!\! \begin{array}{c} #1 \\ #2 \end{array} \!\! \right)}
\newcommand{\matt}[2]{\left( \!\! \begin{array}{cc} #1 \\ #2 \end{array} \!\! \right)}
\renewcommand{\Re}{\mathrm{Re}}
\renewcommand{\Im}{\mathrm{Im}}
\newcommand{\av}[1]{\left\langle #1 \right\rangle}

\newcommand{\pref}[1]{(\ref{#1})}
\newcommand{\eqnref}[1]{(\ref{#1})}

\newcommand{\hr}{\par\vspace{-5ex}\noindent\rule{\textwidth}{1pt}\par\vspace{-1ex}}

\newcommand{\qt}[1]{\textbf{#1}\\}

\newcommand{\extra}{--- Optional ---\ \mbox{}}

\newcommand{\code}[1]{\texttt{#1}}

%%%%% page breaks %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\newcommand{\continue}{\ifprintanswers%
\else
\vfill\hspace*{\fill}$\rightarrow$\newpage%
\fi}
\newcommand{\continuepage}{\ifprintanswers%
\newpage
\else
\vfill\hspace*{\fill}$\rightarrow$\newpage%
\fi}
\newcommand{\newsolutionpage}{\ifprintanswers%
\newpage%
\else
\fi}

%%%%% hyperref %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage[breaklinks=true,bookmarks=true,bookmarksopen=true,pdfpagemode=UseNone,pdfstartview=FitH,colorlinks=true,citecolor=blue!50!black,linkcolor=blue!50!black,urlcolor=blue!50!black]{hyperref}