MAYBE Proof: ConCon could not decide confluence of the system. \cite{ALS94}, Theorem 4.1 does not apply. ConCon could not decide whether all critical pairs are joinable or not. s(x) = gcd(s(x), m(x, x)) <= lt(x, x) = true: For all conditions c 'tcap(c.lhs)' is unifiable with c.rhs.