YES # Compositional parallel critical pair system (Shintani and Hirokawa 2022). Consider the left-linear TRS R: W(B(x)) -> W(x) B(I(x)) -> J(x) W(I(x)) -> W(J(x)) Let C be the following subset of R: (empty) The parallel critical pair system PCPS(R,C) is: W(B(I(x1_1))) -> W(J(x1_1)) W(B(I(x1_1))) -> W(I(x1_1)) All pairs in PCP(R) are joinable and PCPS(R,C)/R is terminating. Therefore, the confluence of R follows from that of C. # emptiness The empty TRS is confluent.