YES Problem: i(0()) -> 0() +(0(),y) -> y +(x,0()) -> x i(i(x)) -> x +(i(x),x) -> 0() +(x,i(x)) -> 0() i(+(x,y)) -> +(i(x),i(y)) +(x,+(y,z)) -> +(+(x,y),z) +(+(x,i(y)),y) -> x +(+(x,y),i(y)) -> x Proof: DP Processor: DPs: i#(+(x,y)) -> i#(y) i#(+(x,y)) -> i#(x) i#(+(x,y)) -> +#(i(x),i(y)) +#(x,+(y,z)) -> +#(x,y) +#(x,+(y,z)) -> +#(+(x,y),z) TRS: i(0()) -> 0() +(0(),y) -> y +(x,0()) -> x i(i(x)) -> x +(i(x),x) -> 0() +(x,i(x)) -> 0() i(+(x,y)) -> +(i(x),i(y)) +(x,+(y,z)) -> +(+(x,y),z) +(+(x,i(y)),y) -> x +(+(x,y),i(y)) -> x Matrix Interpretation Processor: dim=1 usable rules: i(0()) -> 0() +(0(),y) -> y +(x,0()) -> x i(i(x)) -> x +(i(x),x) -> 0() +(x,i(x)) -> 0() i(+(x,y)) -> +(i(x),i(y)) +(x,+(y,z)) -> +(+(x,y),z) +(+(x,i(y)),y) -> x +(+(x,y),i(y)) -> x interpretation: [+#](x0, x1) = x1 + 4, [i#](x0) = x0 + 6, [+](x0, x1) = x0 + 5x1 + 1, [i](x0) = 4x0, [0] = 0 orientation: i#(+(x,y)) = x + 5y + 7 >= y + 6 = i#(y) i#(+(x,y)) = x + 5y + 7 >= x + 6 = i#(x) i#(+(x,y)) = x + 5y + 7 >= 4y + 4 = +#(i(x),i(y)) +#(x,+(y,z)) = y + 5z + 5 >= y + 4 = +#(x,y) +#(x,+(y,z)) = y + 5z + 5 >= z + 4 = +#(+(x,y),z) i(0()) = 0 >= 0 = 0() +(0(),y) = 5y + 1 >= y = y +(x,0()) = x + 1 >= x = x i(i(x)) = 16x >= x = x +(i(x),x) = 9x + 1 >= 0 = 0() +(x,i(x)) = 21x + 1 >= 0 = 0() i(+(x,y)) = 4x + 20y + 4 >= 4x + 20y + 1 = +(i(x),i(y)) +(x,+(y,z)) = x + 5y + 25z + 6 >= x + 5y + 5z + 2 = +(+(x,y),z) +(+(x,i(y)),y) = x + 25y + 2 >= x = x +(+(x,y),i(y)) = x + 25y + 2 >= x = x problem: DPs: TRS: i(0()) -> 0() +(0(),y) -> y +(x,0()) -> x i(i(x)) -> x +(i(x),x) -> 0() +(x,i(x)) -> 0() i(+(x,y)) -> +(i(x),i(y)) +(x,+(y,z)) -> +(+(x,y),z) +(+(x,i(y)),y) -> x +(+(x,y),i(y)) -> x Qed