YES Problem: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(0(),y) -> 0() mod(s(x),0()) -> 0() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) Proof: DP Processor: DPs: le#(s(x),s(y)) -> le#(x,y) minus#(s(x),y) -> le#(s(x),y) minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) if_minus#(false(),s(x),y) -> minus#(x,y) mod#(s(x),s(y)) -> le#(y,x) mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) if_mod#(true(),s(x),s(y)) -> minus#(x,y) if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(0(),y) -> 0() mod(s(x),0()) -> 0() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) Usable Rule Processor: DPs: le#(s(x),s(y)) -> le#(x,y) minus#(s(x),y) -> le#(s(x),y) minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) if_minus#(false(),s(x),y) -> minus#(x,y) mod#(s(x),s(y)) -> le#(y,x) mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) if_mod#(true(),s(x),s(y)) -> minus#(x,y) if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) TRS: le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) le(0(),y) -> true() minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) Matrix Interpretation Processor: dim=1 usable rules: minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) interpretation: [if_mod#](x0, x1, x2) = 2x1 + x2, [mod#](x0, x1) = 2x0 + x1 + 5, [if_minus#](x0, x1, x2) = x1 + 2, [minus#](x0, x1) = x0 + 3, [le#](x0, x1) = x0, [if_minus](x0, x1, x2) = x1, [minus](x0, x1) = x0, [false] = 0, [s](x0) = x0 + 4, [true] = 0, [le](x0, x1) = 0, [0] = 0 orientation: le#(s(x),s(y)) = x + 4 >= x = le#(x,y) minus#(s(x),y) = x + 7 >= x + 4 = le#(s(x),y) minus#(s(x),y) = x + 7 >= x + 6 = if_minus#(le(s(x),y),s(x),y) if_minus#(false(),s(x),y) = x + 6 >= x + 3 = minus#(x,y) mod#(s(x),s(y)) = 2x + y + 17 >= y = le#(y,x) mod#(s(x),s(y)) = 2x + y + 17 >= 2x + y + 12 = if_mod#(le(y,x),s(x),s(y)) if_mod#(true(),s(x),s(y)) = 2x + y + 12 >= x + 3 = minus#(x,y) if_mod#(true(),s(x),s(y)) = 2x + y + 12 >= 2x + y + 9 = mod#(minus(x,y),s(y)) le(s(x),0()) = 0 >= 0 = false() le(s(x),s(y)) = 0 >= 0 = le(x,y) le(0(),y) = 0 >= 0 = true() minus(0(),y) = 0 >= 0 = 0() minus(s(x),y) = x + 4 >= x + 4 = if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) = x + 4 >= 0 = 0() if_minus(false(),s(x),y) = x + 4 >= x + 4 = s(minus(x,y)) problem: DPs: TRS: le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) le(0(),y) -> true() minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) Qed