YES # Compositional parallel rule labeling (Shintani and Hirokawa 2022). Consider the left-linear TRS R: F(x,y) -> c(A()) G(x) -> x h(x) -> c(x) Let C be the following subset of R: (empty) All parallel critical peaks (except C's) are decreasing wrt rule labeling: phi(F(x,y) -> c(A())) = 1 phi(G(x) -> x) = 1 phi(h(x) -> c(x)) = 1 psi(F(x,y) -> c(A())) = 1 psi(G(x) -> x) = 1 psi(h(x) -> c(x)) = 1 Therefore, the confluence of R follows from that of C. # Compositional parallel critical pair system (Shintani and Hirokawa 2022). Consider the left-linear TRS R: (empty) Let C be the following subset of R: (empty) The parallel critical pair system PCPS(R,C) is: (empty) The TRS R is locally confluent and PCPS(R,C)/R is terminating. Therefore, the confluence of R follows from that of C. # Emptiness. The empty TRS is confluent.