Hardy pp. 8 Beals pp. 23 Hardy (p.6) presents this derivation in conjunction with evaluation of Grandi's series 1 − 1 + 1 − 1 + ....
Hardy pp. 8 Beals pp. 23 Hardy (p.6) 结合格兰迪级数1 − 1 + 1 − 1 + …的计算提出了此推导过程。