Dear Cheerful Logicians and Friends of Logic, Before getting to the week's events, two notes. First, The Canadian Society for Epistemology is hosting their annual conference CSE 2020: Deduction, Dialogue, Discourse. I think a number of members are likely to be interested. The topic of the conference is "the nature and role of deductive reasoning," which was chosen in light of the forthcoming book by Catarina Dutilh Novaes. More detail about the conference can be found at their website: http://sce-cse.recherche.usherbrooke.ca/cse-2020/ or on the supergroup member groups calendar.
Second, if you are a member group and would like to host your videos on the supergroup's youtube channel, get in touch, and I am happy to work with you to help make this possible. Now to the week's events: there are four listed on the calendar at this time; one on Monday, one on Thursday, and two on Friday. Details follow. Supergroup Talk Speaker: Damian Szmuc (CONICET and University of Buenos Aires) Title: The fragment of Classical Logic that respects the Variable-Sharing Principle Time and Date: Thursday, October 8 19:00 GMT-5 *Link: * https://ksu.zoom.us/j/95209188832?pwd=OWRuUS9UaDBlbnk5SnhzbFFJZzBOdz09 *Meeting ID:* 952 0918 8832 *Passcode:* sharing Talks by Other Groups: *Logic and Metaphysics Workshop* (CUNY) *Speaker: *Oliver Marshall (UNAM) *Title: *Mathematical Information Content *Time and Date: *Monday, October 5, 15:15 GMT-5 *Link: * https://gc-cuny.zoom.us/j/93214231899?pwd=Um5MZ25sUVp4YXQvZ3pXMXVOcmpzQT09 *Meeting ID: *932 1423 1899 *Passcode: *692542 *Abstract: *Alonzo Church formulated several logistic theories of propositions based on three alternative criteria of identity (1949, 1954, 1989, 1993). The most coarse grained of these criteria is Alternative (2), according to which two propositions are identical iff the sentences that express them are necessarily materially equivalent. Alternative (1) is more discerning. According to Alternative (1), two propositions are identical iff the sentences that express them can be obtained from one another by the substitution of synonyms for synonyms and λ-conversion. Church said that he intended this to limn a notion of proposition closely related to Frege’s notion of gedanke, but added that it will not be sufficiently discerning if propositions in the sense of Alternative (1) are taken as objects of assertion and belief (1993). Alternative (0), the most discerning criterion, says that two propositions are identical iff the sentences that express them can be obtained from one another by the substitution of synonyms for synonyms. I argue that Alternative (1) does indeed provide insight into one of the topics that concerned Frege (1884) – namely, abstraction. Then I discuss various counterexamples to Church’s criteria (including one due to Paul Bernays, 1961). I close by proposing a criterion of identity for mathematical information content based on the various examples under discussion. *UConn Logic Group* Speaker: Sam Sanders (TU Darmstadt) Time and Date: Friday, October 9, 10:00 GMT-5 *Title: *Brouwer, Plato, and classification *Abstract: *Classification is an essential part of all the exact sciences, including mathematical logic. The program Reverse Mathematics classifies theorems of ordinary mathematics according to the minimal axioms needed for a proof. We show that the current scale, based on comprehension and discontinuous functions, is not satisfactory as it classifies many intuitively weak statements, like the uncountability of $\mathbb{R}$ or properties of the Riemann integral, in the same rather strong class. We introduce an alternative/complimentary scale with better properties based on (classically valid) continuity axioms from Brouwer’s intuitionistic mathematics. We discuss how these new results provide empirical support for Platonism. *OCIE seminar in HPML* *Speaker: *Larry Moss *Time and Date: *Friday, October 9, 12:00 GMT-5 *Title: *Natural Logic *Link: *contact Stella Moon ([email protected]) for details *Abstract: *This talk reports on work in logic whose goal is the study of inference in language. This leads to what I will call “natural logic”, the enterprise of studying logical inference in languages that look more like natural language than standard logical systems. The talk should appeal to several parts of the OCIE audience: (1) Logicians interested in completeness and complexity results, including results for logical systems that are not first-order. The talk also includes the simplest completeness theorem in all of logic. (2) Philosophers curious about modern revitalizations of term (syllogistic) logic, especially extensions which incorporate relational reasoning. (3) Anyone interested in monotonicity reasoning, where I and many co-workers have results and running programs. Other Notes and Announcements: - *The Logic Supergroup has a YouTube channel!* Recordings of almost all talks are available at https://www.youtube.com/channel/UCqOAS8SHP-5nGjYEE2FE6xw Yay for logic! -- Você está recebendo esta mensagem porque se inscreveu no grupo "LOGICA-L" dos Grupos do Google. Para cancelar inscrição nesse grupo e parar de receber e-mails dele, envie um e-mail para [email protected]. Para ver esta discussão na web, acesse https://groups.google.com/a/dimap.ufrn.br/d/msgid/logica-l/CAMTR9910TiFxTj%2Bzj-1TLcZSC112%2BQA-GKXZdksM7n8wrx9Teg%40mail.gmail.com.
