YES Problem: minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) quot(0(),s(y)) -> 0() quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) Proof: DP Processor: DPs: minus#(s(x),s(y)) -> minus#(x,y) quot#(s(x),s(y)) -> minus#(x,y) quot#(s(x),s(y)) -> quot#(minus(x,y),s(y)) TRS: minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) quot(0(),s(y)) -> 0() quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) Usable Rule Processor: DPs: minus#(s(x),s(y)) -> minus#(x,y) quot#(s(x),s(y)) -> minus#(x,y) quot#(s(x),s(y)) -> quot#(minus(x,y),s(y)) TRS: minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) Arctic Interpretation Processor: dimension: 1 usable rules: minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) interpretation: [quot#](x0, x1) = 4x0, [minus#](x0, x1) = x0, [s](x0) = 2x0 + 0, [minus](x0, x1) = 1x0, [0] = 1 orientation: minus#(s(x),s(y)) = 2x + 0 >= x = minus#(x,y) quot#(s(x),s(y)) = 6x + 4 >= x = minus#(x,y) quot#(s(x),s(y)) = 6x + 4 >= 5x = quot#(minus(x,y),s(y)) minus(x,0()) = 1x >= x = x minus(s(x),s(y)) = 3x + 1 >= 1x = minus(x,y) problem: DPs: TRS: minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) Qed