YES Problem: c(z,x,a()) -> f(b(b(f(z),z),x)) b(y,b(z,a())) -> f(b(c(f(a()),y,z),z)) f(c(c(z,a(),a()),x,a())) -> z Proof: DP Processor: DPs: c#(z,x,a()) -> f#(z) c#(z,x,a()) -> b#(f(z),z) c#(z,x,a()) -> b#(b(f(z),z),x) c#(z,x,a()) -> f#(b(b(f(z),z),x)) b#(y,b(z,a())) -> f#(a()) b#(y,b(z,a())) -> c#(f(a()),y,z) b#(y,b(z,a())) -> b#(c(f(a()),y,z),z) b#(y,b(z,a())) -> f#(b(c(f(a()),y,z),z)) TRS: c(z,x,a()) -> f(b(b(f(z),z),x)) b(y,b(z,a())) -> f(b(c(f(a()),y,z),z)) f(c(c(z,a(),a()),x,a())) -> z Arctic Interpretation Processor: dimension: 1 usable rules: c(z,x,a()) -> f(b(b(f(z),z),x)) b(y,b(z,a())) -> f(b(c(f(a()),y,z),z)) f(c(c(z,a(),a()),x,a())) -> z interpretation: [b#](x0, x1) = 3x0 + 1x1 + 0, [f#](x0) = 0, [c#](x0, x1, x2) = 6x0 + 2x1 + x2 + -16, [b](x0, x1) = 1x0 + 1x1 + 0, [f](x0) = -5x0 + 0, [c](x0, x1, x2) = 3x0 + -1x1 + -3x2 + 0, [a] = 5 orientation: c#(z,x,a()) = 2x + 6z + 5 >= 0 = f#(z) c#(z,x,a()) = 2x + 6z + 5 >= 1z + 3 = b#(f(z),z) c#(z,x,a()) = 2x + 6z + 5 >= 1x + 4z + 4 = b#(b(f(z),z),x) c#(z,x,a()) = 2x + 6z + 5 >= 0 = f#(b(b(f(z),z),x)) b#(y,b(z,a())) = 3y + 2z + 7 >= 0 = f#(a()) b#(y,b(z,a())) = 3y + 2z + 7 >= 2y + z + 6 = c#(f(a()),y,z) b#(y,b(z,a())) = 3y + 2z + 7 >= 2y + 1z + 6 = b#(c(f(a()),y,z),z) b#(y,b(z,a())) = 3y + 2z + 7 >= 0 = f#(b(c(f(a()),y,z),z)) c(z,x,a()) = -1x + 3z + 2 >= -4x + -3z + 0 = f(b(b(f(z),z),x)) b(y,b(z,a())) = 1y + 2z + 7 >= -5y + -4z + 0 = f(b(c(f(a()),y,z),z)) f(c(c(z,a(),a()),x,a())) = -6x + 1z + 2 >= z = z problem: DPs: TRS: c(z,x,a()) -> f(b(b(f(z),z),x)) b(y,b(z,a())) -> f(b(c(f(a()),y,z),z)) f(c(c(z,a(),a()),x,a())) -> z Qed