Problem: +(x,0()) -> x +(x,s(y)) -> s(+(x,y)) d(0()) -> 0() d(s(x)) -> s(s(d(x))) f(0()) -> 0() f(s(x)) -> +(+(s(x),s(x)),s(x)) f(g(0())) -> +(+(g(0()),g(0())),g(0())) g(x) -> s(d(x)) Proof: Church Rosser Transformation Processor (critical pair closing system, Thm 2.11): f(s(x104)) -> +(+(s(x104),s(x104)),s(x104)) g(0()) -> s(d(0())) critical peaks: joinable Matrix Interpretation Processor: dim=1 interpretation: [g](x0) = 4x0 + 6, [f](x0) = 6x0, [d](x0) = x0, [s](x0) = 4x0 + 4, [+](x0, x1) = x0 + 2x1 + 2, [0] = 4 orientation: f(s(x104)) = 24x104 + 24 >= 20x104 + 24 = +(+(s(x104),s(x104)),s(x104)) g(0()) = 22 >= 20 = s(d(0())) problem: f(s(x104)) -> +(+(s(x104),s(x104)),s(x104)) Matrix Interpretation Processor: dim=1 interpretation: [f](x0) = 5x0 + 5, [s](x0) = 4x0 + 2, [+](x0, x1) = x0 + 2x1 + 2 orientation: f(s(x104)) = 20x104 + 15 >= 20x104 + 14 = +(+(s(x104),s(x104)),s(x104)) problem: Qed