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) } 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) } Fail