Começando bem o ano, com dois seminários do Grupo de Lógica, Linguagem, Informação, Teoria e Aplicações em colaboração com o Grupo de Lógica e Filosofia Formal da UFRN.
Local: Auditório do CCET / UFRN Data: 25-Fev-2011, 14:00-16:00 * * * Reasoning about the World as Process --Richard L. Epstein (*) http://advancedreasoningforum.org/Members/Arf's_Resum%C3%A9.pdf Modern formal logic is based on the assumption that the world is made up of things and propositions are about the relations or properties of things. Starting with some hints in our ordinary language, I will show how we can devise a formal logic to reason instead about the world as process-mass. Clarifying that view with the formal language and logic raises questions about how grammar shapes our perceptions of the world and our morality. (*) Founder of the Advanced Reasoning Forum, USA. Author of "Computability: Computable Functions, Logic, and the Foundations of Mathematics", "The Semantic Foundations of Logic" and "Critical Thinking", among others. * * * Librationist Closures --Frode Bjørdal (**) http://www.hf.uio.no/ifikk/personer/vit/fbjordal/index.html Librationism’s name is coined from”libration”, and so baptized because of shifts in perspectives associated with its treatment of paradoxes. It’s a semiformal theory of sorts, and reminds of paraconsistent approaches. But librationism fully respects classical logic in that all its theorems are retained, and none of them contradicted. For paradoxical sentences such as the one stating that Russell’s sort (of all and only sorts that are not self-membered) is a member of itself, librationism proves it, while it also proves its negation. Inference rules are novel, so librationism doesn’t prove the conjunction. The semantics is based on a semi inductive Herzbergerian process, and focuses on one designated model. So librationism is negation complete; this also facilitates an evasion of Curry’s paradox. Librationism is strong. A fixed point construction shows it’s fully impredicative. Recent progress suggests that an arithmetical program may be viable in such a way that one may show that librationism contains countable models of theories much stronger than ZFC; nevertheless, and somewhat surprisingly, Cantor’s entirely valid arguments for uncountable infinites do not hold librationistically, but only serve to show that the premise that certain sorts are not paradoxical must be given up. (**) Professor of the Department of the Department of Philosophy, Classics, History of Art and Ideas, University of Oslo, Norway * * * _______________________________________________ Logica-l mailing list [email protected] http://www.dimap.ufrn.br/cgi-bin/mailman/listinfo/logica-l
