YES # Parallel rule labeling (Zankl et al. 2015). Consider the left-linear TRS R: a(x) -> x a(b(x)) -> c(b(b(a(a(x))))) b(x) -> c(x) c(c(x)) -> x All parallel critical peaks (except C's) are decreasing wrt rule labeling: phi(a(x) -> x) = 2 phi(a(b(x)) -> c(b(b(a(a(x)))))) = 4 phi(b(x) -> c(x)) = 2 phi(c(c(x)) -> x) = 1 psi(a(x) -> x) = 3 psi(a(b(x)) -> c(b(b(a(a(x)))))) = 4 psi(b(x) -> c(x)) = 3 psi(c(c(x)) -> x) = 1