YES TRS: active(2nd(cons(X,cons(Y,Z)))) -> mark(Y) active(from(X)) -> mark(cons(X,from(s(X)))) active(2nd(X)) -> 2nd(active(X)) active(cons(X1,X2)) -> cons(active(X1),X2) active(from(X)) -> from(active(X)) active(s(X)) -> s(active(X)) 2nd(mark(X)) -> mark(2nd(X)) cons(mark(X1),X2) -> mark(cons(X1,X2)) from(mark(X)) -> mark(from(X)) s(mark(X)) -> mark(s(X)) proper(2nd(X)) -> 2nd(proper(X)) proper(cons(X1,X2)) -> cons(proper(X1),proper(X2)) proper(from(X)) -> from(proper(X)) proper(s(X)) -> s(proper(X)) 2nd(ok(X)) -> ok(2nd(X)) cons(ok(X1),ok(X2)) -> ok(cons(X1,X2)) from(ok(X)) -> ok(from(X)) s(ok(X)) -> ok(s(X)) top(mark(X)) -> top(proper(X)) top(ok(X)) -> top(active(X)) max/plus interpretations on N: active_A(x1) = max{0, 7 + x1} active#_A(x1) = max{35, 42 + x1} 2nd_A(x1) = max{10, x1} 2nd#_A(x1) = max{34, 29 + x1} cons_A(x1,x2) = max{12, x1, x2} cons#_A(x1,x2) = max{1, 32 + x1, 32 + x2} mark_A(x1) = max{18, x1} mark#_A(x1) = max{33, 1 + x1} from_A(x1) = max{11, x1} from#_A(x1) = max{43, 25 + x1} s_A(x1) = max{9, x1} s#_A(x1) = max{37, 11 + x1} proper_A(x1) = max{12, -37} proper#_A(x1) = max{0, 32 + x1} ok_A(x1) = max{24, 12 + x1} ok#_A(x1) = max{0, 36} top_A(x1) = max{0, 0} top#_A(x1) = max{54, 37 + x1} precedence: s = top > active > 2nd > mark > cons = proper > from > ok