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