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.
cons(x, cons(y, cons(y', z'))) = cons(y', cons(x, cons(y, z'))) <= lt(x, y') = true, lt(y', y) = true:
For all conditions c 'tcap(c.lhs)' is unifiable with c.rhs.