\(
\newcommand{\V}[1]{\left(\begin{array}{c}#1\end{array}\right)}
\newcommand{\bbbr}{{\mathbb R}}
\newcommand{\bbbc}{{\mathbb C}}
\newcommand{\bbbl}{{\mathbb L}}
\newcommand{\bbbn}{{\mathbb N}}
\newcommand{\Mc}[2]{\left(\begin{array}{*{#1}{c}}#2\end{array}\right)}
\newcommand{\LR}{\Leftrightarrow}
\newcommand{\RA}{\Rightarrow}
\newcommand{\D}{\displaystyle}
\newcommand{\Sum}{\sum\limits}
\)
Dr. Peter Furlan
Technische Universität Dortmund
Fakultät für Mathematik
E-Mail: peter.furlan[at]math.tu-dortmund.de
