MAYBE

Proof:
ConCon could not decide confluence of the system.
\cite{ALS94}, Theorem 4.1 does not apply.
\cite{A14}, Theorem 11.5.9 does not apply.
\cite{O02}, p. 214, Proposition 7.2.50 does not apply.
\cite{O02}, p. 214, Proposition 7.2.50 does not apply.
\cite{GNG13}, Theorem 9 does not apply.
\cite{SMI95}, Corollary 4.7 or 5.3 do not apply.