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