YES Time: 0.019 Problem: Equations: plusAC(plusAC(x2,x3),x4) -> plusAC(x2,plusAC(x3,x4)) plusAC(x2,x3) -> plusAC(x3,x2) plusAC(x2,plusAC(x3,x4)) -> plusAC(plusAC(x2,x3),x4) plusAC(x3,x2) -> plusAC(x2,x3) TRS: f(plusAC(x,y)) -> plusAC(f(x),f(y)) plusAC(x,0()) -> 0() f(0()) -> 0() Proof: AC-KBO Processor: precedence: f > 0 ~ plusAC weight function: [0] = 4, [f](x0) = x0, [plusAC](x0, x1) = x0 + x1 + 1 problem: Equations: plusAC(plusAC(x2,x3),x4) -> plusAC(x2,plusAC(x3,x4)) plusAC(x2,x3) -> plusAC(x3,x2) plusAC(x2,plusAC(x3,x4)) -> plusAC(plusAC(x2,x3),x4) plusAC(x3,x2) -> plusAC(x2,x3) TRS: Qed