YES # Parallel rule labeling (Zankl et al. 2015). Consider the left-linear TRS R: +(x,0()) -> x +(x,s(y)) -> s(+(x,y)) +(0(),y) -> y +(s(x),y) -> s(+(x,y)) inc(x) -> s(x) +(x,y) -> +(y,x) inc(+(x,y)) -> +(inc(x),y) All parallel critical peaks (except C's) are decreasing wrt rule labeling: phi(+(x,0()) -> x) = 3 phi(+(x,s(y)) -> s(+(x,y))) = 3 phi(+(0(),y) -> y) = 4 phi(+(s(x),y) -> s(+(x,y))) = 3 phi(inc(x) -> s(x)) = 3 phi(+(x,y) -> +(y,x)) = 2 phi(inc(+(x,y)) -> +(inc(x),y)) = 7 psi(+(x,0()) -> x) = 6 psi(+(x,s(y)) -> s(+(x,y))) = 5 psi(+(0(),y) -> y) = 6 psi(+(s(x),y) -> s(+(x,y))) = 5 psi(inc(x) -> s(x)) = 1 psi(+(x,y) -> +(y,x)) = 5 psi(inc(+(x,y)) -> +(inc(x),y)) = 6