English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

leMori veRabi Aviezri Fraenkel, who taught me that Games are Math and Math is a Game Abstract: The Berger-Felzenbaum-Fraenkel approach to Covering Systems is exposited. In particular their gorgeous proof of the famous an = an 1 theorem for exact covering systems (found independently by Jamie Simpson), is reviewed, and the analogy of their approach to Boolean tautologies in Disjunctive Normal Form is pointed out. Preface There is more than one way to contribute to the preservation of the human species. The explicit way is to marry and have children, and if your children turn out to be good, you can and should feel proud. But, a more ecient way is to be a matchmaker ,a nd make good matches, and if the couples that you have introduced to each other turn out to have brilliant children, then you may brag about them as though they were your own. This also applies to math. If you have introduced (directly or indirectly) Dr. Reuven to Professor Simeon, and cast the deciding vote in the committee that admitted Mr. Levi to the Ph.D. program, then you are justied in feeling enormous satisfaction when the Reuven-Simeon-Levi collaboration leads to a major breakthrough in a whole area of mathematics. If this collaboration also lead to a MOST BEAUTIFUL proof, from the BOOK of BOOKS, sought out for many years by the BOOK's proposer, and begged by him in hundreds of lectures, then you can REALLY gloat.

How Berger, Felzenbaum and Fraenkel Revolutionized Covering Systems the Same Way that George Boole Revolutionized Logic