YES Problem: *(i(x),x) -> 1() *(1(),y) -> y *(x,0()) -> 0() *(*(x,y),z) -> *(x,*(y,z)) Proof: Polynomial Interpretation Processor: dimension: 1 interpretation: [0] = 4, [1] = 4, [*](x0, x1) = 4x0 + x1 + 2, [i](x0) = 4x0 + 4x0x0 + 1 orientation: *(i(x),x) = 17x + 16x*x + 6 >= 4 = 1() *(1(),y) = y + 18 >= y = y *(x,0()) = 4x + 6 >= 4 = 0() *(*(x,y),z) = 16x + 4y + z + 10 >= 4x + 4y + z + 4 = *(x,*(y,z)) problem: Qed