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