A rigorous elementary proof of the Basel problem [6, 1] ∑n=1∞1n2=π26 is formalized in the Mizar system [3]. This theorem is item 14 from the “Formalizing 100 Theorems” list maintained by Freek Wiedijk at http://www.cs.ru.nl/F.Wiedijk/100/.
@article{bwmeta1.element.doi-10_1515_forma-2017-0014,
author = {Karol P\k ak and Artur Korni\l owicz},
title = {Basel Problem},
journal = {Formalized Mathematics},
volume = {25},
year = {2017},
pages = {149-155},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.doi-10_1515_forma-2017-0014}
}
Karol Pąk; Artur Korniłowicz. Basel Problem. Formalized Mathematics, Tome 25 (2017) pp. 149-155. http://gdmltest.u-ga.fr/item/bwmeta1.element.doi-10_1515_forma-2017-0014/