\documentclass{rtaloop}
\rtalabel{left-sequentiality}


\begin{document}
\begin{problem}{Aart Middeldorp}{}{April 1991}

\begin{abstract}
Is left-sequentiality a decidable property of orthogonal systems?
\end{abstract}

Thatte \cite{T87:ic} showed that an orthogonal constructor-based rewrite
system is left-sequential 
if and only if it is strongly sequential. Does this equivalence
extend to the whole class of orthogonal term-rewriting systems? If not, is
left-sequentiality a decidable property of orthogonal systems?
See also \cite{KM91}.

\end{problem}
\end{document}
