Published Online: Dec 19, 2017
Page range: 227 - 240
Received: Sep 03, 2017
DOI: https://doi.org/10.1515/forma-2017-0022
Keywords
© 2017 Noboru Endou, published by De Gruyter Open
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.
In this article, we formalize in the Mizar system [