BibTeX: 
@article{Banach_SteinhausAFP,
author = {Dominique Unruh and Jose Manuel Rodriguez Caballero},
title = {BanachSteinhaus Theorem},
journal = {Archive of Formal Proofs},
month = may,
year = 2020,
note = {\url{http://isaafp.org/entries/Banach_Steinhaus.html},
Formal proof development},
ISSN = {2150914x},
}
