YES TRS: from(X) -> cons(X,n__from(n__s(X))) first(0(),Z) -> nil() first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) sel(0(),cons(X,Z)) -> X sel(s(X),cons(Y,Z)) -> sel(X,activate(Z)) from(X) -> n__from(X) s(X) -> n__s(X) first(X1,X2) -> n__first(X1,X2) activate(n__from(X)) -> from(activate(X)) activate(n__s(X)) -> s(activate(X)) activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) activate(X) -> X max/plus interpretations on N: from_A(x1) = max{1, x1} from#_A(x1) = max{1, x1} cons_A(x1,x2) = max{1, x1, x2} cons#_A(x1,x2) = max{1, x1, x2} n__from_A(x1) = max{1, x1} n__from#_A(x1) = max{1, x1} n__s_A(x1) = max{1, x1} n__s#_A(x1) = max{1, x1} first_A(x1,x2) = max{3, 3 + x1, 2 + x2} first#_A(x1,x2) = max{3, 3 + x1, 2 + x2} 0_A = 1 0#_A = 1 nil_A = 0 nil#_A = 0 s_A(x1) = max{1, x1} s#_A(x1) = max{1, x1} n__first_A(x1,x2) = max{1, 3 + x1, 2 + x2} n__first#_A(x1,x2) = max{1, 3 + x1, 2 + x2} activate_A(x1) = max{0, x1} activate#_A(x1) = max{0, x1} sel_A(x1,x2) = max{1, 2 + x1, 4 + x2} sel#_A(x1,x2) = max{1, 2 + x1, 4 + x2} precedence: 0 = sel > nil = activate > from = first = s > cons = n__from = n__s = n__first