TRS:
 {           terms(N) -> cons(recip(sqr(N))),
             sqr(0()) -> 0(),
             sqr(s()) -> s(),
             dbl(0()) -> 0(),
             dbl(s()) -> s(),
          add(0(), X) -> X,
          add(s(), Y) -> s(),
        first(0(), X) -> nil(),
  first(s(), cons(Y)) -> cons(Y)}
 MPO:
  Prec:
   terms > sqr, 
   terms > recip, 
   terms > cons, 
   first > nil
   empty
  Strict:
   {}
   Weak:
    {}
  Qed