YES Problem: f(+(x,0())) -> f(x) +(x,+(y,z)) -> +(+(x,y),z) Proof: Matrix Interpretation Processor: dim=1 interpretation: [+](x0, x1) = x0 + x1 + 2, [0] = 1, [f](x0) = x0 + 4 orientation: f(+(x,0())) = x + 7 >= x + 4 = f(x) +(x,+(y,z)) = x + y + z + 4 >= x + y + z + 4 = +(+(x,y),z) problem: +(x,+(y,z)) -> +(+(x,y),z) Matrix Interpretation Processor: dim=1 interpretation: [+](x0, x1) = x0 + 2x1 + 5 orientation: +(x,+(y,z)) = x + 2y + 4z + 15 >= x + 2y + 2z + 10 = +(+(x,y),z) problem: Qed