Conference and Workshop Talks
- Weak theories of operations, types, and truth, OST-meeting in honour of Andrea Cantini, Florence, December 2016.
- A Feferman-style type system for the small Veblen ordinal, Trends in Proof Theory, Hamburg, September 2015.
- Unfolding schematic systems – with an emphasis on inductive definitions, Utrecht Workshop on Proof Theory, Utrecht, April 2015. [pdf]
- A flexible type system for the small Veblen ordinal, Conference on Mathematical Logic,
Oberwolfach, November 2014.
- Unfolding schematic systems: a survey. Humboldt Kolleg Proof, Bern, September 2013.
- Unfolding schematic formal systems: From non-finitist to feasible arithmetic, Special Session on Proof Theory, Logic Colloquium ’12, Manchester, July 2012. [pdf]
- Types and truth in weak applicative theories, Logical Models of Reasoning and Computation, Moscow, February 2012.
- Weak theories of operations, truth and types, Conference on Mathematical Logic,
Oberwolfach, November 2011.
- Weak theories of truth and explicit mathematics, Axiomatic Theories of Truth, Oxford,
September 2011. [pdf]
- Unfolding arithmetic - with an emphasis on finitism, Leeds Symposium on Proof Theory and
Constructivism, Leeds, July 2009. [pdf]
- Primitive recursive selection functions for existential
assertions over abstract algebras, Proof
Theory: Workshop on Logic, Foundational Research, and Metamathematics,
Münster, July 2008. [pdf]
- Weak theories of operations and types, Plenary Lecture, Logic Colloquium '08, Bern, July
2008. [pdf]
- Kripke-Platek set theory over
polynomial time computable arithmetic, Proof, Computation, Complexity '07,
Swansea, Wales, April 2007. [pdf]
- On the proof
theory of type two functionals, Conference
on Mathematical Logic,
Oberwolfach, April 2005. [pdf]
- On bounded
applicative theories and computational complexities, Bounded Arithmetic and
Complexity Classes BACC
2002, Lisbon, June 2002.
- A
proof-theoretic characterization of the basic feasible functionals,
Conference on
Mathematical
Logic, Oberwolfach, April 2002.
- Type-free
applicative systems: a proof-theoretic approach to complexities,
Dagstuhl seminar on
Proof Theory in Computer Science, Dagstuhl, October 2001.
(not delivered because of illness).
- Unfolding finitist arithmetic,
Logic Colloquium 2000,
Paris, July 2000.
- Bounded applicative theories,
Logic Colloquium 2000,
Paris, July 2000.
- Theories
with self-application and computational complexity, Workshop on Proof and Computation,
Munich, November 1999.
- Bar
induction and omega model reflection, Research Workshop on Proof Theory,
Leeds, February 1999.
- Reflective
closures of formal systems, Reflections
Symposium,
Stanford, December 1998.
- Universes in
explicit mathematics and admissible set theory, Workshop on Operations, Sets, and
Types, Castiglioncello, October 1998.
- Metapredicativity,
Plenary lecture,
Logic Colloquium ’98, Prague, August 1998.
- Abstract
computations in type-free applicative systems, Workshop on Proof Theory and
Complexity, Aarhus, August 1998.
- Metapredicativity, Conference on
Mathematical Logic, Oberwolfach, January 1998.
- Aspects of
metapredicativity, Special
Session on Proof Theory, Logic Colloquium ’97,
Leeds, July 1997.
- The unfolding of non-finitist
arithmetic, Workshop on Proof
Theory and Ordinal Analyses, Münster, May 1997.
- The non-constructive μ
operator in explicit mathematics: a survey, Workshop on Applicative Theories and
Explicit Mathematics, Berne, June 1996.
- Systems of explicit mathematics
with primitive recursive operations plus non-constructive μ
operator, 10th International
Congress of Logic, Methodology and Philosophy of Science,
Florence, August 1995.
- Polynomial
time operations in explicit mathematics, Special Session on Proof Theory,
Logic Colloquium ’95, Haifa, August 1995.
- Polynomial
time operations in applicative theories, Conference on Mathematical Logic,
Oberwolfach, April 1995.
- Induction in
applicative theories, EC
Workshop on Proof Theory and Computation, Leeds, September
1994.
- Partiality versus totality in
applicative theories, International
conference on Proof Theory, Provability Logic, and Computation PPC
’94, Berne, March 1994.
- Applicative theories and term
models, Workshop on
Applicative Theories, Berne, March 1994.
Colloquia and Seminar Talks
- Finitely stratified inductive definitions, Stanford Logic Seminar, Stanford, October, 2013. [pdf]
- Weak theories of explicit mathematics and positive truth, Stanford Logic Seminar, Standford, July, 2012.
- Das P-NP-Problem und die Grenzen der praktischen Berechenbarkeit,
Fachschaftstagung Informatik,
Mathematik und Physik, Gymnasium Muristalden, Berne, November
2010. [pdf]
- The unfolding of non-finitist and finitist arithmetic, Philosophy of Mathematics Seminar,
University of Oxford, May 2010.
- Two unfoldings of finitist arithmetic, Proof, Complexity and Verification Seminar,
University of Swansea, Wales, April 2010. [pdf]
- Unfolding arithmetic, Logic Seminar,
University of Florence, December 2008.
- Einige Ideen und Probleme der
theoretischen Informatik, Kolloquium
Informatik und Unterricht, Berne, January 2008. [pdf]
- Unfolding schematic formal
systems, Swiss-South African
Joint Seminar, Berne, January 2007. [pdf]
- Logik im
interdisziplinären Spannungsfeld zwischen Informatik,
Mathematik und Philosophie, Fachschaftstagung
Mathematik,
Gymnasium Köniz, November 2004. [pdf]
- Logik in
Informatik und Mathematik, Forum
Mathematik und Unterricht,
Berne, May 2004.
- Das P-NP-Problem und die
Grenzen der praktischen Berechenbarkeit, Habilitations-Kolloquium, Berne,
June 2001.
- Untyped
applicative theories and computational complexity, Mittag-Leffler seminar,
Institute Mittag-Leffler, Stockholm, March 2001.
- Applicative
theories and classes of computational complexity, Logic Seminar,
University of Florence, May 2000.
- Applikative
Theorien und Komplexität, Computer
Science Colloquium,
University of Tübingen, January 2000.
- The
implicitness program, Philosophical
Colloquium, University of Bonn, November 1999.
- Logik in
Informatik, Mathematik und Philosophie, Theodor Kocher award lecture,
University of Berne, January 1999. [pdf]
- Recent
results in metapredicative proof theory, Stanford Logic Seminar,
March-April 1998.
- Abstrakte Berechnungen in
expliziter Mathematik, Seminar
Theoretische Informatik und Logik, Schloss Münchenwiler,
April 1997.
- Zur Beweistheorie von
applikativen Theorien, PhD
defense, Berne, June 1996.
- Polynomial
time operations in applicative theories, Logic Colloquium,
SRI International, Menlo Park, December 1995.
- Some new
proof-theoretic results about explicit mathematics with
non-constructive μ operator, Stanford Logic Seminar,
October 1995.
- Beweise als Progamme, Colloquium Philosophical Society Berne,
June 1994.
- Numerous talks in the seminar Logik und Informatik (Berne-Zurich),
the colloquium Deduktive Aspekte
von Beweistheorie und Informatik (Berne-Munich), and the
Münchenwiler seminar Logic and
Information (Berne-Fribourg-Neuchâtel).
A list of publications and talks in pdf-format can be downloaded
here.