\documentclass{rtaloop}
\rtalabel{hyper-graph}


\begin{document}
\begin{problem}{D. Plump}{}{June 1993}

\begin{abstract}
  What sufficient conditions make confluence of general (hyper-)graph
  rewriting decidable?
\end{abstract}  
In contrast to term rewriting, confluence of general (hyper-)graph
rewriting---in the ``Berlin approach''---is undecidable, even for
terminating systems \cite{P93:tgr}. What sufficient conditions make
confluence decidable?

\end{problem}
\end{document}