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