Seminário de Lógica Matemática

From ultrafilters to compactness

Sala 6.2.33, FCUL, Lisboa

Por Pedro Filipe (Instituto Superior Técnico, Universidade de Lisboa).

Abstract: The compactness theorem is one of the key ingredients used in Lindstrom's Theorem that characterizes first-order logic and follows directly from Godel's completeness theorem, given the finite nature of proofs. In time, alternative proofs were found that don't require the usage of a formal proof system. In this seminar we will show one of these alternative proofs using ultrafilters and ultraproducts.

16h00
CMAFcIO - Centro de Matemática, Aplicações Fundamentais e Investigação Operacional