YES # Parallel rule labeling (Zankl et al. 2015). Consider the left-linear TRS R: f(0(),0()) -> f(0(),1()) f(1(),0()) -> f(0(),0()) f(x,y) -> f(y,x) All parallel critical peaks (except C's) are decreasing wrt rule labeling: phi(f(0(),0()) -> f(0(),1())) = 5 phi(f(1(),0()) -> f(0(),0())) = 5 phi(f(x,y) -> f(y,x)) = 4 psi(f(0(),0()) -> f(0(),1())) = 1 psi(f(1(),0()) -> f(0(),0())) = 3 psi(f(x,y) -> f(y,x)) = 2