In this article we give definitions of open functions and continuous functions formulated in terms of "balls" of given topological spaces.
@article{bwmeta1.element.doi-10_2478_v10037-010-0019-5,
author = {Artur Korni\l owicz},
title = {Miscellaneous Facts about Open Functions and Continuous Functions},
journal = {Formalized Mathematics},
volume = {18},
year = {2010},
pages = {171-174},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.doi-10_2478_v10037-010-0019-5}
}
Artur Korniłowicz. Miscellaneous Facts about Open Functions and Continuous Functions. Formalized Mathematics, Tome 18 (2010) pp. 171-174. http://gdmltest.u-ga.fr/item/bwmeta1.element.doi-10_2478_v10037-010-0019-5/
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