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: W(B(x)) -> W(x) B(I(x)) -> J(x) W(I(x)) -> W(J(x)) The parallel critical pair system PCPS(R,C) is: (empty) All pairs in PCP(R) are joinable and PCPS(R,C)/R is terminating. Therefore, the confluence of R follows from that of C. # Parallel rule labeling (Zankl et al. 2015). Consider the left-linear TRS R: W(B(x)) -> W(x) B(I(x)) -> J(x) W(I(x)) -> W(J(x)) All parallel critical peaks (except C's) are decreasing wrt rule labeling: phi(W(B(x)) -> W(x)) = 2 phi(B(I(x)) -> J(x)) = 2 phi(W(I(x)) -> W(J(x))) = 1 psi(W(B(x)) -> W(x)) = 2 psi(B(I(x)) -> J(x)) = 2 psi(W(I(x)) -> W(J(x))) = 1