MAYBE
MAYBE
TRS:
 {
              sqr(0()) -> 0(),
             sqr(s(X)) -> s(add(sqr(X), dbl(X))),
              terms(N) -> cons(recip(sqr(N))),
           add(0(), X) -> X,
          add(s(X), Y) -> s(add(X, Y)),
              dbl(0()) -> 0(),
             dbl(s(X)) -> s(s(dbl(X))),
         first(0(), X) -> nil(),
  first(s(X), cons(Y)) -> cons(Y),
             half(0()) -> 0(),
          half(s(0())) -> 0(),
         half(s(s(X))) -> s(half(X)),
          half(dbl(X)) -> X
 }
 DUP: We consider a duplicating system.
  Trs:
   {
                sqr(0()) -> 0(),
               sqr(s(X)) -> s(add(sqr(X), dbl(X))),
                terms(N) -> cons(recip(sqr(N))),
             add(0(), X) -> X,
            add(s(X), Y) -> s(add(X, Y)),
                dbl(0()) -> 0(),
               dbl(s(X)) -> s(s(dbl(X))),
           first(0(), X) -> nil(),
    first(s(X), cons(Y)) -> cons(Y),
               half(0()) -> 0(),
            half(s(0())) -> 0(),
           half(s(s(X))) -> s(half(X)),
            half(dbl(X)) -> X
   }
  Fail