Consider the TRS R consisting of the rewrite rules

1: 2nd(cons(X,n__cons(Y,Z))) -> activate(Y)
2: from(X) -> cons(X,n__from(s(X)))
3: cons(X1,X2) -> n__cons(X1,X2)
4: from(X) -> n__from(X)
5: activate(n__cons(X1,X2)) -> cons(X1,X2)
6: activate(n__from(X)) -> from(X)
7: activate(X) -> X

There are 4 dependency pairs:

8: 2nd#(cons(X,n__cons(Y,Z))) -> ACTIVATE(Y)
9: FROM(X) -> CONS(X,n__from(s(X)))
10: ACTIVATE(n__cons(X1,X2)) -> CONS(X1,X2)
11: ACTIVATE(n__from(X)) -> FROM(X)

The approximated dependency graph contains no SCCs
and hence the TRS is trivially terminating.