YES TRS: f(s(X),X) -> f(X,a(X)) f(X,c(X)) -> f(s(X),X) f(X,X) -> c(X) max/plus interpretations on N: f_A(x1,x2) = max{0, 3 + x1, 3 + x2} f#_A(x1,x2) = max{0, -2, 4 + x2} s_A(x1) = max{2, -1 + x1} s#_A(x1) = max{2, 6} a_A(x1) = max{1, -1} a#_A(x1) = max{5, -1} c_A(x1) = max{3, 1 + x1} c#_A(x1) = max{1, -3} precedence: s > f > a = c