YES # Compositional critical pair system (Shintani and Hirokawa 2022). Consider the left-linear TRS R: foo(0(x)) -> 0(s(p(p(p(s(s(s(p(s(x)))))))))) foo(s(x)) -> p(s(p(p(p(s(s(p(s(s(p(s(foo(p(p(s(s(p(s(bar(p(p(s(s(p(s(x)))))))))))))))))))))))))) bar(0(x)) -> 0(p(s(s(s(x))))) bar(s(x)) -> p(s(p(p(s(s(foo(s(p(p(s(s(x)))))))))))) p(p(s(x))) -> p(x) p(s(x)) -> x p(0(x)) -> 0(s(s(s(s(x))))) Let C be the following subset of R: (empty) The critical pair system CPS(R,C) is: p(p(s(y0))) -> p(y0) The TRS R is locally confluent and CPS(R,C)/R is terminating. Therefore, the confluence of R follows from that of C. # Emptiness. The empty TRS is confluent.