This symposium (a.k.a. the Feferfest) is centered around proof theoretically inspired foundational investigations. Solomon Feferman has been a contributor to these investigations during the last forty years in a most systematic and significant way, and the main themes of the Symposium are themes in his work. The Symposium is a tribute to him on the occasion of his 70-th birthday—a tribute both to his specific contributions and to his influence on the direction of current research.
December 11; 100 Cordura Hall
Opening remarks. J. Barwise
Session I: Proof theoretic ordinals
(Chair: G. Mints).
W. Pohlers; Proof-theoretic ordinals for theories in the language of (second order) arithmetic and set theory
J. Avigad; Ordinal analysis without proofs
R. Sommer; Iterating reflection
Session II: Foundational reductions
(Chair: W. Sieg).
P. Martin-Lof; Modelling versus Tarski semantics.
J. Barwise; Symbolic and presymbolic logic
J. van Bentham; Logical constants: the variable fortunes of an elusive notion December 12; Gates Building, B03
Session III: Formalizations in restricted systems
(Chair: S. Buss).
G. Takeuti; Godel sentences of bounded arithmetic
R. Constable; Admiring proof reflections and working with them
U. Kohlenbach; Classical analysis in weak systems of finite type
S. Simpson; Predicativity: the outer limits
Session IV: Applicative and self-applicative theories
(Chair: M. Beeson).
D. Scott; Project update: logics of types and computations
M. Rathjen; Monotone inductive definitions in explicit mathematics
A. Cantini; On extensionality, uniformity and comprehension in explicit mathematics
I. Mason/ C. Talcott; Feferman-Landin logic
December 13; Gates Building, B03
Session V: Philosophy and history of modern mathematical thought
(Chair: D. Follesdal).
C. Parsons; Reflections on predicativity
J. Dawson; The unity of mathematics—a foundational touchstone?
W. Sieg; Calculations by man and machine
W. Tait; Some remarks about finitism
Session VI: Generalized computation and reflective closure (Chair: J. Etchemendy).