Problem: +(0(),y) -> y +(x,s(y)) -> s(+(y,x)) +(x,y) -> +(y,x) Proof: AT confluence processor Complete TRS T' of input TRS: +(0(),y) -> y +(x,s(y)) -> s(+(y,x)) +(y,0()) -> y +(s(y),x) -> s(+(x,y)) +(x,y) -> +(y,x) T' = (P union S) with TRS P:+(x,y) -> +(y,x) TRS S:+(0(),y) -> y +(x,s(y)) -> s(+(y,x)) +(y,0()) -> y +(s(y),x) -> s(+(x,y)) S is linear and P is reversible. CP(S,S) = s(y) = s(+(y,0())), 0() = 0(), s(+(x209,0())) = s(x209), s(+(x211,s(y))) = s(+(s(x211),y)), s(y) = s(+(0(),y)), s(+(s(y),x214)) = s(+(y,s(x214))), s(+(0(),x216)) = s(x216) CP(S,P union P^-1) = y = +(y,0()), x = +(x,0()), s(+(x233,x)) = +(s(x233),x), s(+(x235,y)) = +(s(x235),y), x = +(0(),x), y = +(0(),y), s(+(y,x238)) = +(y,s(x238)), s(+(x,x240)) = +(x,s(x240)) CP(P union P^-1,S) = +(y,0()) = y, +(s(y),x) = s(+(y,x)), +(0(),y) = y, +(x,s(y)) = s(+(x,y)) We have to check termination of S: Matrix Interpretation Processor: dim=1 interpretation: [s](x0) = x0, [+](x0, x1) = 2x0 + 2x1, [0] = 1 orientation: +(0(),y) = 2y + 2 >= y = y +(x,s(y)) = 2x + 2y >= 2x + 2y = s(+(y,x)) +(y,0()) = 2y + 2 >= y = y +(s(y),x) = 2x + 2y >= 2x + 2y = s(+(x,y)) problem: +(x,s(y)) -> s(+(y,x)) +(s(y),x) -> s(+(x,y)) Matrix Interpretation Processor: dim=1 interpretation: [s](x0) = x0 + 1, [+](x0, x1) = 2x0 + 2x1 + 2 orientation: +(x,s(y)) = 2x + 2y + 4 >= 2x + 2y + 3 = s(+(y,x)) +(s(y),x) = 2x + 2y + 4 >= 2x + 2y + 3 = s(+(x,y)) problem: Qed