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)) *(1(),0()) -> 0() *(1(),s(y)) -> s(*(1(),y)) +(x,y) -> +(y,x) +(+(x,y),z) -> +(x,+(y,z)) All parallel critical peaks (except C's) are decreasing wrt rule labeling: phi(+(x,0()) -> x) = 6 phi(+(x,s(y)) -> s(+(x,y))) = 3 phi(+(0(),y) -> y) = 6 phi(+(s(x),y) -> s(+(x,y))) = 3 phi(*(1(),0()) -> 0()) = 1 phi(*(1(),s(y)) -> s(*(1(),y))) = 1 phi(+(x,y) -> +(y,x)) = 5 phi(+(+(x,y),z) -> +(x,+(y,z))) = 8 psi(+(x,0()) -> x) = 6 psi(+(x,s(y)) -> s(+(x,y))) = 1 psi(+(0(),y) -> y) = 6 psi(+(s(x),y) -> s(+(x,y))) = 2 psi(*(1(),0()) -> 0()) = 1 psi(*(1(),s(y)) -> s(*(1(),y))) = 1 psi(+(x,y) -> +(y,x)) = 4 psi(+(+(x,y),z) -> +(x,+(y,z))) = 7