\documentclass{rtaloop}
\rtalabel{semigroup}


\begin{document}
\begin{problem}{Franz Baader}{\cite{B90:cade}}{June 1993}

\begin{abstract}
Does there exist a semigroup theory for which there is a reduced canonical
term-rewriting system that is not length decreasing?
\end{abstract}

Does there exist a semigroup theory (without constants in the equations) for
which there is a reduced canonical term-rewriting system (with the right-hand
side and subterms of the left in normal form) that is not length decreasing?

\end{problem}
\end{document}