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)) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),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) gcd#(s(x),s(y)) -> le#(y,x) gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) if_gcd#(true(),s(x),s(y)) -> minus#(x,y) if_gcd#(true(),s(x),s(y)) -> gcd#(minus(x,y),s(y)) if_gcd#(false(),s(x),s(y)) -> minus#(y,x) if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) 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)) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) Matrix Interpretation Processor: dim=1 interpretation: [if_gcd#](x0, x1, x2) = 4x1 + 2x2 + 4, [gcd#](x0, x1) = 4x0 + 2x1 + 5, [if_minus#](x0, x1, x2) = x0 + 4x1 + 3x2, [minus#](x0, x1) = 4x0 + 3x1 + 3, [le#](x0, x1) = 2x1 + 4, [if_gcd](x0, x1, x2) = 3x0 + x1 + x2 + 3, [gcd](x0, x1) = 2x0 + x1 + 5, [if_minus](x0, x1, x2) = 2x1 + 1, [minus](x0, x1) = 2x0 + 1, [false] = 0, [s](x0) = 4x0 + 4, [true] = 0, [le](x0, x1) = 2, [0] = 0 orientation: le#(s(x),s(y)) = 8y + 12 >= 2y + 4 = le#(x,y) minus#(s(x),y) = 16x + 3y + 19 >= 2y + 4 = le#(s(x),y) minus#(s(x),y) = 16x + 3y + 19 >= 16x + 3y + 18 = if_minus#(le(s(x),y),s(x),y) if_minus#(false(),s(x),y) = 16x + 3y + 16 >= 4x + 3y + 3 = minus#(x,y) gcd#(s(x),s(y)) = 16x + 8y + 29 >= 2x + 4 = le#(y,x) gcd#(s(x),s(y)) = 16x + 8y + 29 >= 16x + 8y + 28 = if_gcd#(le(y,x),s(x),s(y)) if_gcd#(true(),s(x),s(y)) = 16x + 8y + 28 >= 4x + 3y + 3 = minus#(x,y) if_gcd#(true(),s(x),s(y)) = 16x + 8y + 28 >= 8x + 8y + 17 = gcd#(minus(x,y),s(y)) if_gcd#(false(),s(x),s(y)) = 16x + 8y + 28 >= 3x + 4y + 3 = minus#(y,x) if_gcd#(false(),s(x),s(y)) = 16x + 8y + 28 >= 8x + 8y + 17 = gcd#(minus(y,x),s(x)) le(0(),y) = 2 >= 0 = true() le(s(x),0()) = 2 >= 0 = false() le(s(x),s(y)) = 2 >= 2 = le(x,y) minus(0(),y) = 1 >= 0 = 0() minus(s(x),y) = 8x + 9 >= 8x + 9 = if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) = 8x + 9 >= 0 = 0() if_minus(false(),s(x),y) = 8x + 9 >= 8x + 8 = s(minus(x,y)) gcd(0(),y) = y + 5 >= y = y gcd(s(x),0()) = 8x + 13 >= 4x + 4 = s(x) gcd(s(x),s(y)) = 8x + 4y + 17 >= 4x + 4y + 17 = if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) = 4x + 4y + 11 >= 4x + 4y + 11 = gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) = 4x + 4y + 11 >= 4x + 4y + 11 = gcd(minus(y,x),s(x)) problem: DPs: 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)) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) Qed