5-8 May 2009
Uppsala, Sweden
Philosophy and Foundations of Mathematics : Epistemological and Ontological Aspects, at the Swedish Collegium for Advanced Study, Uppsala, May 5-8, 2009 - a conference dedicated to Per Martin-Lf on the occasion of his retirement. Speakers Peter Aczel: TBA Mark van Atten: Different times: Kant and Brouwer on real numbers Steve Awodey: Type theory and homotopy theory Thierry Coquand: Forcing and type theory Peter Dybjer: Program testing and constructive validity Juliet Floyd: Wittgenstein, Gdel and Turing Jean-Yves Girard: Towards non-commutative foundations Sten Lindstrm: The Curry-Fitch's knowability paradox revisited Per Martin-Lf: Logic: epistemological or ontological? Colin McLarty: Identity and existence in categorical foundations Peter Pagin: Assertion, truth and judgment Erik Palmgren: Formal topology and foundational problems Christine Paulin-Mohring: Reasoning on randomized programs in Coq Jan von Plato: Aristotles deductive logic: a proof-theoretical study Dag Prawitz: TBA Aarne Ranta: Levels of abstraction in language and logic Michael Rathjen: The boundaries of intuitionistic type theory Giovanni Sambin: A minimalist foundation of mathematics Anton Setzer: Coalgebras as types determined by their elimination rules Stewart Shapiro: An "i" for an i: singular terms, uniqueness and reference Wilfried Sieg: Reductive structuralism Jan Smith: Can Hume's analysis of causality tell us something about the rules of logic? Sren Stenlund: On the notion finite numbers Gran Sundholm: Three key-features of Martin-Lf's philosophy of logic William Tait: The myth of intuition Jouko Vnnen: Second order logic, set theory and foundations of mathematics Scope and aim The aim of the conference is to bring together philosophers, mathematicians, and logicians to penetrate current and historically important problems in the philosophy and foundations of mathematics. Swedish logicians and philosophers have made important contributions to the foundations and philosophy of mathematics, at least since the end of the 1960s. In philosophy, one has been concerned with the opposition between constructivism and classical mathematics and the different ontological and epistemological views that are reflected in this opposition. A central philosophical question concerns the nature of the abstract entities of mathematics: do they exist independently of our epistemic acts (realism, or Platonism) or are they somehow constituted by these acts (idealism)? Significant contributions have been made to the foundations of mathematics, for example in proof theory, proof-theoretic semantics and constructive type theory. These contributions have had a strong impact on areas of computer science, e.g. through Martin-Lf's type theory. Two important alternative foundational programmes that are actively pursued today are predicativistic constructivism and category-theoretic foundations. Predicativistic constructivism can be based on Martin-Lf constructive type theory, Aczel's constructive set theory, or similar systems. The practice of the Bishop school of constructive mathematics fits well into this framework. Associated philosophical foundations are meaning theories in the tradition of Wittgenstein, Dummett, Prawitz and Martin-Lf. What is the relation between proof-theoretical semantics in the tradition of Gentzen, Prawitz, and Martin-Lf and Wittgensteinian or other accounts of meaning-as-use? What can proof-theoretical analysis tell us about the scope and limits of constructive and (generalized) predicative mathematics? To what extent is it possible to reduce classical mathematical frameworks to constructive ones? Such reductions often reveal computational content of classical existence proofs. Is computational content enough to solve the epistemological questions? A central concern for the conference will be to compare the different foundational frameworks - classical set theory, constructive type theory, and category theory - both from a philosophical and a logical point of view. The general theme of the conference, however, will be broader and encompass different areas of philosophy and foundations of mathematics, in particular the interplay between ontological and epistemological considerations. Venue The workshop will take place at the Swedish Collegium for Advanced Study (SCAS), Linneanum, Thunbergsvgen 2, Uppsala, Sweden. Organization and programme committee Peter Dybjer, Sten Lindstrm, Erik Palmgren (Chair), Dag Prawitz, Sren Stenlund, Viggo Stoltenberg-Hansen. Programme The scientific programme starts at 10.00 on Tuesday, May 5 and ends at 16.00 on Friday, May 8. A conference dinner is planned for Friday evening. More details about the programme will appear in a few weeks. Attendance Attendance is open, and there is no registration fee. However, anyone planning to attend should preregister by emailing PFM@math.uu.se no later than April 15, 2009. (For reasons of space the number of participants will be limited to 90.) Sponsors Swedish Research Council (Vetenskapsrdet) - Department of Mathematics, Stockholm University - Department of Philosophy, Stockholm University - Department of Mathematics, Uppsala University - Centre for Interdisciplinary Mathematics, Uppsala University - Department of Philosophy, Uppsala University - Department of Computer Science and Engineering, Chalmers University of Technology and Gothenburg University - The Swedish Collegium for Advanced Study, Uppsala - Swedish National Committee for Logic, Methodology and Philosophy of Science. Webpage http://www.math.uu.se/PFM/