header.tex

\documentclass[a4paper,12pt,twoside]{article}
\usepackage{fourier}
\usepackage{polynom}
\usepackage[ngerman]{babel}
\usepackage[leqno,tbtags,nointlimits]{amsmath}
\usepackage{amssymb,amsthm,amsfonts}
\usepackage{graphicx}
\usepackage{ifthen}
%\usepackage{gauss}
\usepackage{tikz}
\usepackage{mathtools}
\usepackage{makeidx}
\usepackage{fancyhdr,lastpage}
\usepackage{enumerate}
\usepackage[onehalfspacing]{setspace}
\usepackage{mdsymbol}
\usepackage{marvosym}
\usepackage{cancel}
\usepackage{pgfplots}
\usepackage{color}
\usepackage{bigints}
\usepackage{array}
\usepackage{mdframed}
\usepackage{marginnote}
\usetikzlibrary{trees,automata,arrows,shapes,decorations.pathmorphing,matrix}
\pagestyle{fancy}
\usepackage{hyperref}
\fancyhf{} %--Clear all fields
\renewcommand\sectionmark[1]{ \markboth{\thesection\ \textsc{#1}}{}}
\fancyhead[LO,RE]{\small \leftmark}
\fancyhead[LE,RO]{ \rightmark}
\fancyfoot{} % clear all footer fields
\fancyfoot[LE,RO]{\thepage}
\newcommand{\cd}{\cdot}
\newcommand{\C}{\mathbb{C}}
\newcommand{\Z}{\mathbb{Z}}
\renewcommand{\i}{\item}
\newcommand{\U}{\mathcal{U}}
\newcommand{\N}{\mathbb{N}}
\newcommand{\R}{\mathbb{R}}
\newcommand{\raum}[1]{\left\langle#1\right\rangle}
\DeclarePairedDelimiter{\ceil}{\lceil}{\rceil}
\DeclarePairedDelimiter{\floor}{\lfloor}{\rfloor}
\DeclarePairedDelimiter{\norm}{\Vert}{\Vert}
\usepackage[normalem]{ulem}
\usepackage{blkarray}
\usepackage{stmaryrd}
\usepackage{titletoc}
\usepackage{empheq}
\usepackage{multirow,bigdelim}
\newcommand{\Hesse}{\mathrm{H}(f)}
\newcommand{\vardelta}{\raisebox{5.3pt}{\rotatebox{180}{\varrho}}}
\newcommand{\abs}[1]{\lvert #1 \rvert}
\renewcommand\headrule{{\color{gray}%
\hrule height 2pt width\headwidth
\vspace{1pt}%
\hrule height 1pt width\headwidth
\vspace{-4pt}}}
\makeatletter
\newcommand{\resetHeadWidth}{\fancy@setoffs}
\makeatother
\newcommand{\limit}[1]{\displaystyle \lim_{#1}}
\usepgfplotslibrary{fillbetween}
\pgfplotsset{compat=1.9}
\newcommand\vektor[3]{\begin{pmatrix}
#1\\#2\\#3
\end{pmatrix}}
\newcommand\vektort[2]{\begin{pmatrix}
#1\\#2
\end{pmatrix}}
\newcommand\vektorf[4]{\begin{pmatrix}
#1\\#2\\#3\\#4
\end{pmatrix}}
\newcount\vectorcount
\renewcommand*\vector[1]{%
  \global\vectorcount#1
  \begin{pmatrix}
    \vectornext
}
\def\vectornext#1{%
  #1
  \global\advance\vectorcount-1
    \ifnum\vectorcount>0
      \\
      \expandafter\vectornext
    \else
      \end{pmatrix}
    \fi
}
\makeatletter
% Matrix beliebiger Größe (Bsp.: a,b;c,d)
\def\@gobblesecondoftwo#1#2{#1}
\NewDocumentCommand\Matrix{>{\SplitList;}m}{%
  \begin{pmatrix*}[r]
    \ProcessList{#1}\@Matrix%
  \end{pmatrix*}
}
\NewDocumentCommand\@Matrix{>{\SplitList,}m}{%
  \expandafter\expandafter\expandafter\@gobblesecondoftwo
  \ProcessList{#1}\@@Matrix \\%
}
\def\@@Matrix#1{&#1}

% patch gmatrix to look like normal matrix in 'align'
\patchcmd\g@matrix
 {\vbox\bgroup}
 {\vbox\bgroup\normalbaselines} % restore the standard baselineskip
 {}{}
\makeatother
\DeclareMathOperator{\Grad}{Grad}
% vertical line for gmatrix
\newcommand{\gvline}{%
  \hspace{-\arraycolsep}%
  \strut\vrule % the `\vrule` is as high and deep as a strut
  \hspace{-\arraycolsep}%
}
\makeindex