Problem: +(0(),y) -> y +(x,s(y)) -> s(+(x,y)) +(+(x,y),z) -> +(x,+(y,z)) +(x,y) -> +(y,x) Proof: AT confluence processor Complete TRS T' of input TRS: +(0(),y) -> y +(x,s(y)) -> s(+(x,y)) +(y,0()) -> y +(s(y),x) -> s(+(y,x)) +(+(x,y),z) -> +(x,+(y,z)) +(x,y) -> +(y,x) T' = (P union S) with TRS P:+(+(x,y),z) -> +(x,+(y,z)) +(x,y) -> +(y,x) TRS S:+(0(),y) -> y +(x,s(y)) -> s(+(x,y)) +(y,0()) -> y +(s(y),x) -> s(+(y,x)) S is linear and P is reversible. CP(S,S) = s(y) = s(+(0(),y)), 0() = 0(), s(+(0(),x342)) = s(x342), s(+(s(y),x344)) = s(+(y,s(x344))), s(y) = s(+(y,0())), s(+(x347,s(y))) = s(+(s(x347),y)), s(+(x349,0())) = s(x349) CP(S,P union P^-1) = +(y,z) = +(0(),+(y,z)), y = +(y,0()), +(y,z) = +(+(0(),y),z), +(x,z) = +(+(x,0()),z), x = +(x,0()), s(+(+(x,y),x393)) = +(x,+(y,s(x393))), +(s(+(x,x395)),z) = +(x,+(s(x395),z)), s(+(x,x397)) = +(s(x397),x), +(x,s(+(y,x399))) = +(+(x,y),s(x399)), s(+(y,x401)) = +(s(x401),y), +(x,y) = +(x,+(y,0())), +(x,z) = +(x,+(0(),z)), x = +(0(),x), +(x,y) = +(+(x,y),0()), y = +(0(),y), +(s(+(x407,y)),z) = +(s(x407),+(y,z)), s(+(x409,y)) = +(y,s(x409)), s(+(x411,+(y,z))) = +(+(s(x411),y),z), +(x,s(+(x413,z))) = +(+(x,s(x413)),z), s(+(x415,x)) = +(x,s(x415)) CP(P union P^-1,S) = +(x497,+(x498,s(y))) = s(+(+(x497,x498),y)), +(x500,+(x501,0())) = +(x500,x501), +(y,0()) = y, +(s(y),x) = s(+(x,y)), +(0(),y) = y, +(x,s(y)) = s(+(y,x)), +(+(0(),x512),x513) = +(x512,x513), +(+(s(y),x515),x516) = s(+(y,+(x515,x516))) We have to check termination of S: Matrix Interpretation Processor: dim=1 interpretation: [+](x0, x1) = 3x0 + 4x1, [0] = 6, [s](x0) = x0 + 6 orientation: +(0(),y) = 4y + 18 >= y = y +(x,s(y)) = 3x + 4y + 24 >= 3x + 4y + 6 = s(+(x,y)) +(y,0()) = 3y + 24 >= y = y +(s(y),x) = 4x + 3y + 18 >= 4x + 3y + 6 = s(+(y,x)) problem: Qed