YES Problem: plus(plus(X,Y),Z) -> plus(X,plus(Y,Z)) times(X,s(Y)) -> plus(X,times(Y,X)) Proof: DP Processor: DPs: plus#(plus(X,Y),Z) -> plus#(Y,Z) plus#(plus(X,Y),Z) -> plus#(X,plus(Y,Z)) times#(X,s(Y)) -> times#(Y,X) times#(X,s(Y)) -> plus#(X,times(Y,X)) TRS: plus(plus(X,Y),Z) -> plus(X,plus(Y,Z)) times(X,s(Y)) -> plus(X,times(Y,X)) Matrix Interpretation Processor: dim=1 usable rules: interpretation: [times#](x0, x1) = x0 + x1 + 2, [plus#](x0, x1) = x0 + 4, [times](x0, x1) = 4x1, [s](x0) = x0 + 4, [plus](x0, x1) = 2x0 + x1 + 1 orientation: plus#(plus(X,Y),Z) = 2X + Y + 5 >= Y + 4 = plus#(Y,Z) plus#(plus(X,Y),Z) = 2X + Y + 5 >= X + 4 = plus#(X,plus(Y,Z)) times#(X,s(Y)) = X + Y + 6 >= X + Y + 2 = times#(Y,X) times#(X,s(Y)) = X + Y + 6 >= X + 4 = plus#(X,times(Y,X)) plus(plus(X,Y),Z) = 4X + 2Y + Z + 3 >= 2X + 2Y + Z + 2 = plus(X,plus(Y,Z)) times(X,s(Y)) = 4Y + 16 >= 6X + 1 = plus(X,times(Y,X)) problem: DPs: TRS: plus(plus(X,Y),Z) -> plus(X,plus(Y,Z)) times(X,s(Y)) -> plus(X,times(Y,X)) Qed