YES Time: 0.539 Problem: Equations: timesAC(timesAC(x1,x2),x3) -> timesAC(x1,timesAC(x2,x3)) timesAC(x1,x2) -> timesAC(x2,x1) timesAC(x1,timesAC(x2,x3)) -> timesAC(timesAC(x1,x2),x3) timesAC(x2,x1) -> timesAC(x1,x2) TRS: p(s(x)) -> x fac(0()) -> s(0()) fac(s(x)) -> timesAC(s(x),fac(p(s(x)))) Proof: Matrix Interpretation Processor: dimension: 2 interpretation: [1 4] [3] [fac](x0) = [1 8]x0 + [2], [1] [0] = [0], [4 0] [2] [p](x0) = [1 0]x0 + [0], [1 1] [0] [s](x0) = [2 3]x0 + [1], [0] [timesAC](x0, x1) = x0 + x1 + [3] orientation: [4 4] [2] p(s(x)) = [1 1]x + [0] >= x = x [4] [1] fac(0()) = [3] >= [3] = s(0()) [9 13] [7 ] [9 9 ] [5] fac(s(x)) = [17 25]x + [10] >= [14 15]x + [8] = timesAC(s(x),fac(p(s(x)))) problem: Equations: timesAC(timesAC(x1,x2),x3) -> timesAC(x1,timesAC(x2,x3)) timesAC(x1,x2) -> timesAC(x2,x1) timesAC(x1,timesAC(x2,x3)) -> timesAC(timesAC(x1,x2),x3) timesAC(x2,x1) -> timesAC(x1,x2) TRS: Qed