YES # Parallel rule labeling (Zankl et al. 2015). Consider the left-linear TRS R: f(a(),b()) -> c() a() -> a'() b() -> b'() c() -> f(a'(),b()) c() -> f(a(),b'()) c() -> f(a(),b()) All parallel critical peaks (except C's) are decreasing wrt rule labeling: phi(f(a(),b()) -> c()) = 1 phi(a() -> a'()) = 3 phi(b() -> b'()) = 7 phi(c() -> f(a'(),b())) = 2 phi(c() -> f(a(),b'())) = 8 phi(c() -> f(a(),b())) = 8 psi(f(a(),b()) -> c()) = 3 psi(a() -> a'()) = 6 psi(b() -> b'()) = 4 psi(c() -> f(a'(),b())) = 5 psi(c() -> f(a(),b'())) = 4 psi(c() -> f(a(),b())) = 9