\documentclass[compress, 9pt, german, t]{beamer}
\usepackage{etex}

\usepackage[ngerman]{babel}
\uselanguage{German}
\languagepath{German}

\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}

\usepackage{arev}
\usepackage{mathpazo}
\usepackage{microtype}

\usepackage{url}
\usepackage{listings}
\usepackage{xcolor}
\usepackage{tabu}
\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=1.8}
\usetikzlibrary{automata}
\usetikzlibrary{calc}
\usetikzlibrary{shapes}
\usetikzlibrary{positioning}
\usetikzlibrary{chains}

\usepackage{amsmath}
\usepackage{mathdots}
\usepackage{mathtools}
\mathtoolsset{showonlyrefs,showmanualtags}
\usepackage{mathrsfs}
\usepackage{csquotes}

\usepackage{beamerthemeLEA2}
\setbeamercovered{transparent}

\newcommand{\N}{\mathbb{N}}
\newcommand{\Z}{\mathbb{Z}}
\newcommand{\Q}{\mathbb{Q}}
\newcommand{\R}{\mathbb{R}}
\newcommand{\C}{\mathbb{C}}
\newcommand{\Prob}{\mathrm{P}}
\newcommand{\Oh}{\mathcal{O}}

\newcommand{\true}{\mathrm{true}}
\newcommand{\false}{\mathrm{false}}

\newcommand{\abs}[1]{\left\vert #1 \right\vert}
\newcommand{\powerset}[1]{\mathcal{P}\left( #1 \right)}
\newcommand{\setnot}[1]{\overline{#1}}
\newcommand{\setsymdiff}{\,\triangle\,}
\newcommand{\alg}[1]{\left\langle #1 \right\rangle}
\DeclareMathOperator{\ind}{ind}
\DeclareMathOperator{\ord}{ord}
\DeclareMathOperator{\ggt}{ggT}

\newcommand{\rel}[1]{\,\mathrm{#1}\,}
\DeclareRobustCommand{\stirlingone}{\genfrac{[}{]}{0pt}{}}
\DeclareRobustCommand{\stirlingtwo}{\genfrac\{\}{0pt}{}}

\newcommand{\defeq}{\coloneqq} %Mathtools already defines this

\pgfdeclarelayer{background}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,foreground}

\tikzstyle{edge} = [draw,very thick,->,>=latex]
\tikzstyle{pretty} = [circle,thick,draw,fill=tumblue!10]
\tikzstyle{every edge} = [edge]
\tikzstyle{every state} = [pretty]
\tikzstyle{automaton} = [shorten >=1pt, node distance = 3cm, auto, bend angle=20, initial text=]
\tikzstyle{small} = [every node/.style={scale=0.5}, baseline=(current bounding box.north), font=\LARGE]

\tikzstyle{every edge} = [edge]
\tikzstyle{every state} = [pretty]

\tikzstyle{rectangular} = [draw, rectangle, minimum size = 6mm, fill=tumblue!10]
\tikzstyle{tape} = [on chain, rectangular]
\tikzstyle{active} = [fill=tumred!10]
\tikzstyle{head} = [arrow box, draw, minimum size=5mm, arrow box arrows={east:.25cm, west:0.25cm, north:0.2cm}, fill=tumred!10]
\tikzstyle{machine} = [rectangle, draw, minimum width=2cm, minimum height=1cm, inner sep=3mm, fill=tumgreen!10]

\newcommand{\pcp}[2]{ \begin{tabu}{c} #1 \\ \tabucline{-} #2 \\ \end{tabu} }
\newcommand{\chomsky}[4]{\draw[rect, #1, fill=#1!10, #2] ({5.5 - #3 * 0.5}, {0 + #3 * 0.3}) rectangle ({-5.5 + #3 * 0.5}, {7 - #3 * 1.2}) node[caption] {#4};}
\newcommand{\langclass}[4]{\draw[rect, #1, fill=#1!20, #2] ({5.2 - #3 * 0.5}, {0 + #3 * 0.12}) rectangle ({-5.2 + #3 * 0.5}, {7.5 - #3 * 0.75}) node[caption] {#4};}