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