---- CR(R) ---- [van Oostrom, RTA 2008]. R: p(x) -> q(x) p(x) -> r(x) q(x) -> s(p(x)) r(x) -> s(p(x)) s(x) -> f(p(x)) Label: [p(x) -> q(x)] = 1 [p(x) -> r(x)] = 2 [q(x) -> s(p(x))] = 0 [r(x) -> s(p(x))] = 0 [s(x) -> f(p(x))] = 0