\documentclass{rtaloop}
\rtalabel{trs-lattices}
\begin{document}
\begin{solvedproblem}{Freese}{}{June 1993}
\begin{abstract}
Is there a finite, normal form, associative-commutative term-rewriting
system for lattices?
\end{abstract}
\begin{remark}
J Jezek, J. B. Nation, and R. Freese \cite{freese93pc} have shown that there
is no finite, normal form, associative-commutative term-rewriting system for
lattices. This is somewhat surprising because every lattice term is equivalent
under lattice theory to a shortest term which is unique up to associativity
and commutativity (known as ``Whitman canonical form'').
\end{remark}
\end{solvedproblem}
\end{document}