YES 1 decompositions #1 ----------- 1: +(x1,0()) -> x1 2: +(x2,s(x3)) -> s(+(x2,x3)) 3: d(0()) -> 0() 4: d(s(x4)) -> s(s(d(x4))) 5: f(0()) -> 0() 6: f(s(x5)) -> +(+(s(x5),s(x5)),s(x5)) 7: f(g(0())) -> +(+(g(0()),g(0())),g(0())) 8: g(x6) -> s(d(x6)) @Knuth and Bendix' criterion --- R 1: +(x1,0()) -> x1 2: +(x2,s(x3)) -> s(+(x2,x3)) 3: d(0()) -> 0() 4: d(s(x4)) -> s(s(d(x4))) 5: f(0()) -> 0() 6: f(s(x5)) -> +(+(s(x5),s(x5)),s(x5)) 7: f(g(0())) -> +(+(g(0()),g(0())),g(0())) 8: g(x6) -> s(d(x6)) --- S 1: +(x1,0()) -> x1 2: +(x2,s(x3)) -> s(+(x2,x3)) 3: d(0()) -> 0() 4: d(s(x4)) -> s(s(d(x4))) 5: f(0()) -> 0() 6: f(s(x5)) -> +(+(s(x5),s(x5)),s(x5)) 7: f(g(0())) -> +(+(g(0()),g(0())),g(0())) 8: g(x6) -> s(d(x6))