About this article
Published Online: Jan 09, 2021
Page range: 155 - 171
Accepted: May 19, 2020
DOI: https://doi.org/10.2478/forma-2020-0014
Keywords
© 2020 Sebastian Koch, published by Sciendo
This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.
In this article the union and intersection of a set of graphs are formalized in the Mizar system [5], based on the formalization of graphs in [7].