Problem: +(x,0()) -> x +(x,s(y)) -> s(+(x,y)) +(0(),y) -> y +(s(x),y) -> s(+(x,y)) *(k(),0()) -> 0() *(k(),s(y)) -> +(k(),*(k(),y)) +(x,y) -> +(y,x) +(+(x,y),z) -> +(x,+(y,z)) *(k(),+(x,y)) -> +(*(k(),x),*(k(),y)) Proof: AT confluence processor Complete TRS T' of input TRS: +(x,0()) -> x +(x,s(y)) -> s(+(x,y)) +(0(),y) -> y +(s(x),y) -> s(+(x,y)) *(k(),0()) -> 0() *(k(),s(y)) -> +(k(),*(k(),y)) *(k(),+(x,y)) -> +(*(k(),x),*(k(),y)) +(x,y) -> +(y,x) +(+(x,y),z) -> +(x,+(y,z)) +(z,+(x,y)) -> +(+(y,z),x) +(z,+(x,y)) -> +(x,+(z,y)) T' = (P union S) with TRS P:+(x,y) -> +(y,x) +(+(x,y),z) -> +(x,+(y,z)) +(z,+(x,y)) -> +(+(y,z),x) +(z,+(x,y)) -> +(x,+(z,y)) TRS S:+(x,0()) -> x +(x,s(y)) -> s(+(x,y)) +(0(),y) -> y +(s(x),y) -> s(+(x,y)) *(k(),0()) -> 0() *(k(),s(y)) -> +(k(),*(k(),y)) *(k(),+(x,y)) -> +(*(k(),x),*(k(),y)) S is linear and P is reversible. CP(S,S) = 0() = 0(), s(x) = s(+(x,0())), *(k(),x) = +(*(k(),x),*(k(),0())), s(+(0(),x1538)) = s(x1538), s(+(s(x),x1540)) = s(+(x,s(x1540))), *(k(),s(+(x,x1542))) = +(*(k(),x),*(k(),s(x1542))), s(y) = s(+(0(),y)), *(k(),y) = +(*(k(),0()),*(k(),y)), s(+(x1546,0())) = s(x1546), s(+(x1548,s(y))) = s(+(s(x1548),y)), *(k(),s(+(x1550,y))) = +(*(k(),s(x1550)),*(k(),y)) CP(S,P union P^-1) = x = +(0(),x), +(x,y) = +(x,+(y,0())), +(x,z) = +(x,+(0(),z)), +(z,x) = +(+(0(),z),x), +(z,x) = +(x,+(z,0())), y = +(0(),y), +(x,y) = +(+(x,y),0()), +(y,z) = +(z,+(0(),y)), +(y,x) = +(0(),+(x,y)), +(x,z) = +(z,+(x,0())), s(+(x,x1689)) = +(s(x1689),x), s(+(+(x,y),x1691)) = +(x,+(y,s(x1691))), +(s(+(x,x1693)),z) = +(x,+(s(x1693),z)), +(z,s(+(x,x1695))) = +(+(s(x1695),z),x), +(z,s(+(x,x1697))) = +(x,+(z,s(x1697))), s(+(y,x1699)) = +(s(x1699),y), +(x,s(+(y,x1701))) = +(+(x,y),s(x1701)), s(+(+(y,z),x1703)) = +(z,+(s(x1703),y)), +(s(+(y,x1705)),x) = +(s(x1705),+(x,y)), +(x,s(+(z,x1707))) = +(z,+(x,s(x1707))), y = +(y,0()), +(y,z) = +(0(),+(y,z)), +(x,y) = +(+(y,0()),x), +(z,y) = +(+(y,z),0()), +(x,y) = +(x,+(0(),y)), +(z,y) = +(0(),+(z,y)), x = +(x,0()), +(y,z) = +(+(0(),y),z), +(x,z) = +(+(x,0()),z), +(z,x) = +(z,+(x,0())), +(z,y) = +(z,+(0(),y)), +(x,y) = +(0(),+(x,y)), s(+(x1720,y)) = +(y,s(x1720)), +(s(+(x1722,y)),z) = +(s(x1722),+(y,z)), s(+(x1724,+(x,y))) = +(+(y,s(x1724)),x), +(z,s(+(x1726,y))) = +(+(y,z),s(x1726)), s(+(x1728,+(x,y))) = +(x,+(s(x1728),y)), +(z,s(+(x1730,y))) = +(s(x1730),+(z,y)), s(+(x1732,x)) = +(x,s(x1732)), s(+(x1734,+(y,z))) = +(+(s(x1734),y),z), +(x,s(+(x1736,z))) = +(+(x,s(x1736)),z), +(s(+(x1738,z)),x) = +(z,+(x,s(x1738))), s(+(x1740,+(z,y))) = +(z,+(s(x1740),y)), +(x,s(+(x1742,y))) = +(s(x1742),+(x,y)) CP(P union P^-1,S) = +(0(),x) = x, +(s(y),x) = s(+(x,y)), +(y,0()) = y, +(y,s(x)) = s(+(x,y)), *(k(),+(y,x)) = +(*(k(),x),*(k(),y)), +(x2128,+(x2129,0())) = +(x2128,x2129), +(x2131,+(x2132,s(y))) = s(+(+(x2131,x2132),y)), *(k(),+(x2134,+(x2135,y))) = +(*(k(),+(x2134,x2135)),*(k(),y)), +(+(x2139,0()),x2138) = +(x2138,x2139), +(+(x2142,s(x)),x2141) = s(+(x,+(x2141,x2142))), *(k(),+(+(x2145,x),x2144)) = +(*(k(),x),*(k(),+(x2144,x2145))), +(x2147,+(0(),x2148)) = +(x2147,x2148), +(x2150,+(s(x),x2151)) = s(+(x,+(x2150,x2151))), *(k(),+(x2153,+(x,x2154))) = +(*(k(),x),*(k(),+(x2153,x2154))), +(+(0(),x2166),x2167) = +(x2166,x2167), +(+(s(x),x2169),x2170) = s(+(x,+(x2169,x2170))), *(k(),+(+(x,x2172),x2173)) = +(*(k(),x),*(k(),+(x2172,x2173))), +(x2175,+(0(),x2174)) = +(x2174,x2175), +(x2178,+(s(y),x2177)) = s(+(+(x2177,x2178),y)), *(k(),+(x2181,+(y,x2180))) = +(*(k(),+(x2180,x2181)),*(k(),y)), +(x2184,+(0(),x2185)) = +(x2184,x2185), +(x2187,+(s(x),x2188)) = s(+(x,+(x2187,x2188))), *(k(),+(x2190,+(x,x2191))) = +(*(k(),x),*(k(),+(x2190,x2191))) We have to check termination of S: Matrix Interpretation Processor: dim=1 interpretation: [*](x0, x1) = 4x0 + x1, [+](x0, x1) = x0 + x1 + 5, [k] = 0, [0] = 0, [s](x0) = x0 + 5 orientation: +(x,0()) = x + 5 >= x = x +(x,s(y)) = x + y + 10 >= x + y + 10 = s(+(x,y)) +(0(),y) = y + 5 >= y = y +(s(x),y) = x + y + 10 >= x + y + 10 = s(+(x,y)) *(k(),0()) = 0 >= 0 = 0() *(k(),s(y)) = y + 5 >= y + 5 = +(k(),*(k(),y)) *(k(),+(x,y)) = x + y + 5 >= x + y + 5 = +(*(k(),x),*(k(),y)) problem: +(x,s(y)) -> s(+(x,y)) +(s(x),y) -> s(+(x,y)) *(k(),0()) -> 0() *(k(),s(y)) -> +(k(),*(k(),y)) *(k(),+(x,y)) -> +(*(k(),x),*(k(),y)) Matrix Interpretation Processor: dim=1 interpretation: [*](x0, x1) = x0 + 3x1, [+](x0, x1) = x0 + x1, [k] = 0, [0] = 1, [s](x0) = x0 + 6 orientation: +(x,s(y)) = x + y + 6 >= x + y + 6 = s(+(x,y)) +(s(x),y) = x + y + 6 >= x + y + 6 = s(+(x,y)) *(k(),0()) = 3 >= 1 = 0() *(k(),s(y)) = 3y + 18 >= 3y = +(k(),*(k(),y)) *(k(),+(x,y)) = 3x + 3y >= 3x + 3y = +(*(k(),x),*(k(),y)) problem: +(x,s(y)) -> s(+(x,y)) +(s(x),y) -> s(+(x,y)) *(k(),+(x,y)) -> +(*(k(),x),*(k(),y)) Matrix Interpretation Processor: dim=1 interpretation: [*](x0, x1) = x0 + 4x1 + 3, [+](x0, x1) = x0 + x1 + 6, [k] = 2, [s](x0) = x0 orientation: +(x,s(y)) = x + y + 6 >= x + y + 6 = s(+(x,y)) +(s(x),y) = x + y + 6 >= x + y + 6 = s(+(x,y)) *(k(),+(x,y)) = 4x + 4y + 29 >= 4x + 4y + 16 = +(*(k(),x),*(k(),y)) problem: +(x,s(y)) -> s(+(x,y)) +(s(x),y) -> s(+(x,y)) Matrix Interpretation Processor: dim=1 interpretation: [+](x0, x1) = 2x0 + x1 + 1, [s](x0) = x0 + 1 orientation: +(x,s(y)) = 2x + y + 2 >= 2x + y + 2 = s(+(x,y)) +(s(x),y) = 2x + y + 3 >= 2x + y + 2 = s(+(x,y)) problem: +(x,s(y)) -> s(+(x,y)) Matrix Interpretation Processor: dim=1 interpretation: [+](x0, x1) = x0 + 4x1, [s](x0) = x0 + 5 orientation: +(x,s(y)) = x + 4y + 20 >= x + 4y + 5 = s(+(x,y)) problem: Qed