YES # parallel critical pair closing system (Shintani and Hirokawa 2022) Consider the left-linear TRS R: 0(1(2(3(4(x))))) -> 0(2(1(3(4(x))))) 0(5(1(2(4(3(x)))))) -> 0(5(2(1(4(3(x)))))) 0(5(2(4(1(3(x)))))) -> 0(1(5(2(4(3(x)))))) 0(5(3(1(2(4(x)))))) -> 0(1(5(3(2(4(x)))))) 0(5(4(1(3(2(x)))))) -> 0(5(4(3(1(2(x)))))) Let C be the following subset of R: (empty) The TRS R is left-linear and all parallel critical pairs are joinable by C. Therefore, the confluence of R follows from that of C. # emptiness The empty TRS is confluent.