YES # Compositional parallel critical pair system (Shintani and Hirokawa 2022). Consider the left-linear TRS R: F(H(x),y) -> G(H(x)) H(I(x)) -> I(x) F(I(x),y) -> G(I(x)) Let C be the following subset of R: F(H(x),y) -> G(H(x)) H(I(x)) -> I(x) F(I(x),y) -> G(I(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: F(H(x),y) -> G(H(x)) H(I(x)) -> I(x) F(I(x),y) -> G(I(x)) All parallel critical peaks (except C's) are decreasing wrt rule labeling: phi(F(H(x),y) -> G(H(x))) = 2 phi(H(I(x)) -> I(x)) = 3 phi(F(I(x),y) -> G(I(x))) = 1 psi(F(H(x),y) -> G(H(x))) = 1 psi(H(I(x)) -> I(x)) = 2 psi(F(I(x),y) -> G(I(x))) = 2