The series' terms (1, −2, 3, −4, ...) do not approach 0; therefore 1 − 2 + 3 − 4 + ... diverges by the term test. For later reference, it will also be useful to see the divergence on a fundamental level. By definition, the convergence or divergence of an infinite series is determined by the convergence or divergence of its sequence of partial sums, and the partial sums of 1 − 2 + 3 − 4 + ... are:[1]