Sergey Odintsov spoke on the topic of "Moisil's Modal Logic and Related Systems"

Sergey Odintsov, a leading researcher at the S.L. Sobolev Institute of Mathematics of the Siberian Branch of the Russian Academy of Sciences, made a presentation on "Moisil's Modal Logic and Related Systems" at the seminar "Formal Philosophy" on June 27.

Abstract

This report focuses on the article "Modal Logic" by Romanian logician Grigore Moisil, published in 1942. In this work, Moisil developed a theory of modal operators—impossibility, chance, necessity, and possibility—using algebraic foundations. He defined a logic with two dual implications: one forming a residual pair with conjunction, and the other with disjunction. This system anticipated S. Rauscher's bi-intuitionistic logic. Moisil also introduced systems equivalent to Dummett's chain logic, Belnap and Dunn's first-degree entailment (FDE), and Leitgeb's HYPE logic.

The research presented is based on the article:

S. Drobyshevich, S.Odintsov, H.Wansing, Moisil's Modal Logic and Related Systems, in: K.Bimbo (Ed.) Relevance Logics and other Tools of Reasoning, Essays in Honor of J. Michael Dunn, College Publications, 2022