Jan Łukasiewicz was a Polish logician and philosopher who is best known for Polish notation and Łukasiewicz logic. His work centred on philosophical logic, mathematical logic and history of logic. He thought innovatively about traditional propositional logic, the principle of non-contradiction and the law of excluded middle, offering one of the earliest systems of many-valued logic. Contemporary research on Aristotelian logic also builds on innovative works by Łukasiewicz, which applied methods from modern logic to the formalization of Aristotle's syllogistic.
George Stephen Boolos was an American philosopher and a mathematical logician who taught at the Massachusetts Institute of Technology.
Kazimierz Ajdukiewicz was a Polish philosopher and logician, a prominent figure in the Lwów–Warsaw school of logic. He originated many novel ideas in semantics. Among these was categorial grammar, a highly flexible framework for the analysis of natural language syntax and (indirectly) semantics that remains a major influence on work in formal linguistics. Ajdukiewicz's fields of research were model theory and the philosophy of science.
Formal epistemology uses formal methods from decision theory, logic, probability theory and computability theory to model and reason about issues of epistemological interest. Work in this area spans several academic fields, including philosophy, computer science, economics, and statistics. The focus of formal epistemology has tended to differ somewhat from that of traditional epistemology, with topics like uncertainty, induction, and belief revision garnering more attention than the analysis of knowledge, skepticism, and issues with justification.
Vincent Fella Rune Møller Hendricks is a Danish philosopher and logician. He holds a doctoral degree (PhD) and a habilitation (dr.phil) in philosophy and is Professor of Formal Philosophy and Director of the Center for Information and Bubble Studies (CIBS) at University of Copenhagen, Denmark. He was previously Professor of Formal Philosophy at Roskilde University, Denmark. He is member of IIP, the Institut International de Philosophie in Paris.
Stanisław Jaśkowski was a Polish logician who made important contributions to proof theory and formal semantics. He was a student of Jan Łukasiewicz and a member of the Lwów–Warsaw School of Logic. He is regarded as one of the founders of natural deduction, which he discovered independently of Gerhard Gentzen in the 1930s. He is also known for his research into paraconsistent logic. Upon his death, his name was added to the Genius Wall of Fame. He was the President (rector) of the Nicolaus Copernicus University in Toruń.
In mathematical logic, abstract algebraic logic is the study of the algebraization of deductive systems arising as an abstraction of the well-known Lindenbaum–Tarski algebra, and how the resulting algebras are related to logical systems.
A metatheory or meta-theory is a theory on a subject matter that is a theory in itself. Analyses or descriptions of an existing theory would be considered meta-theories. If the subject matter of a theoretical statement consists of one or multiple theories, it would also be called a meta-theory. For mathematics and mathematical logic, a metatheory is a mathematical theory about another mathematical theory. Meta-theoretical investigations are part of the philosophy of science. The topic of metascience is an attempt to use scientific knowledge to improve the practice of science itself.
In mathematics and philosophy, Łukasiewicz logic is a non-classical, many-valued logic. It was originally defined in the early 20th century by Jan Łukasiewicz as a three-valued modal logic; it was later generalized to n-valued as well as infinitely-many-valued (ℵ0-valued) variants, both propositional and first order. The ℵ0-valued version was published in 1930 by Łukasiewicz and Alfred Tarski; consequently it is sometimes called the Łukasiewicz–Tarski logic. It belongs to the classes of t-norm fuzzy logics and substructural logics.
Jan Hertrich-Woleński is a Polish philosopher specializing in the history of the Lwów–Warsaw school of logic and in analytic philosophy.
Jerzy Giedymin was a philosopher and historian of mathematics and science.
Walter Alexandre Carnielli is a Brazilian mathematician, logician, and philosopher, who works as a full professor of Logic at the State University of Campinas. After obtaining his Bachelor and M.Sc. degrees in mathematics at the State University of Campinas, he also obtained his Ph.D. in 1984 there under the supervision of Newton da Costa; subsequently, he worked as a post-doc at the University of California at Berkeley, following an invitation by Leon Henkin.
Charles Leonard Hamblin was an Australian philosopher, logician, and computer pioneer, as well as a professor of philosophy at the New South Wales University of Technology in Sydney.
Andrzej Grzegorczyk was a Polish logician, mathematician, philosopher, and ethicist noted for his work in computability, mathematical logic and the foundations of mathematics.
Janina Hosiasson-Lindenbaum was a Polish logician and philosopher. She published some twenty research papers along with translations into Polish of three books by Bertrand Russell. The main focus of her writings was on foundational problems related to probability, induction and confirmation. She is noted especially for authoring the first printed discussion of the Raven Paradox which she credits to Carl Hempel and the probabilistic solution she outlined to it. Shot by the Gestapo in 1942, she, like her husband Adolf Lindenbaum, and many other eminent representatives of Polish logic, shared the fate of millions of Jews murdered on Polish soil by the Nazis.
Jerzy Słupecki (1904–1987) was a Polish mathematician and logician.
Henryk Hiż was a Polish analytical philosopher specializing in linguistics, philosophy of language, logic, mathematics and ethics, active for most of his life in the United States, one of the youngest representatives of the Lwów–Warsaw school.
Stella Ewa Orłowska is a Polish logician. Her research centers on the concept that everything in logic and set theory can be expressed in terms of relations, and has used this idea to publish works on deduction systems and model theory for non-classical logic, and logics of non-deterministic and incomplete information. She is a professor at the National Institute of Telecommunications in Warsaw, and the former president of the Polish Association for Logic and Philosophy of Science.
Urszula Wybraniec-Skardowska is a Polish logician whose research topics have included rough sets and inference rules for rejecting certain propositions as invalid.
