"Proofs and types", 25 years later

26–28 March 2015 at the Dipartimento di "Filosofia, Comunicazione, Spettacolo", via Ostiense 234, Rome




Representation and axiomatization: power and limits

19–21 March 2015 at the IHPST in Paris




Modeling hypothetical reasoning: validity, inference, and paradoxes

19–20 February 2015 at the IHPST in Paris




Conference on Hypothetical Reasoning

23–24 August 2014 in Tübingen

The conference is held in conjunction with ESSLLI 2014.





29–30 May 2014 at the IHPST in Paris




Functions, Proofs, Constructions

21–23 February 2014 in Tübingen




Proofs that and proofs why

14–15 November 2013 at the IHPST in Paris




Proofs and Programs: From Semantics to Complexity

16–17 May 2013 at the Université Jean Moulin – Lyon 3

Salle de la Rotonde, 18 rue Chevreul – 69007 Lyon




Three Lectures on Dialogues

Date: 9h-11h on Thursdays 14, 21 and 28 March 2013
Location: Paris, IHPST (2e étage, salle de conférences)
Docent: Thomas Piecha

Lecture notes




Second Conference on Proof-Theoretic Semantics

Date: 8-10 March 2013
Location: Universität Tübingen, Schloss Hohentübingen, Seminarraum 165

Invited Speakers

  • Sergei N. Artëmov (City University of New York): On Brouwer-Heyting-Kolmogorov provability semantics
  • Kosta Došen (Mathematical Institute, SANU): Two Ways of General Proof Theory
  • Roy Dyckhoff (University of St Andrews): Generalised elimination rules
  • Lars Hallnäs (University of Borås): On the proof theoretic foundations of set theory
  • Wilfrid Hodges (Dartmoor): The choice of semantics as a methodological question
  • Reinhard Kahle (Universidade Nova de Lisboa): The mode of presentation
  • Dag Prawitz (Stockholm University): Remarks on relations between Gentzen and Heyting inspired PTS
  • Giovanni Sambin (Università di Padova): Unification of logics by reflection
  • Göran Sundholm (Universiteit Leiden): BHK and Brouwer's Theory of the Creative Subject
  • William W. Tait (University of Chicago): Compositional semantics for predicate logic: Eliminating bound variables from formulas and deductions
  • Gabriele Usberti (Università degli Studi di Siena): Intuitionism, the Paradox of Knowability and Empirical Negation
  • Jan von Plato (University of Helsinki): Explicit composition and its application in normalization proofs
  • Heinrich Wansing (Ruhr University Bochum): A two-sorted typed lambda-calculus

Contributed Speakers

  • Walter Dean (University of Warwick): Kreisel's second clause and the Theory of Constructions (with H. Kurokawa)
  • Hidenori Kurokawa (City University of New York)
  • Yoshihiro Maruyama (University of Oxford): On Paradoxes in Proof-Theoretic Semantics



Cross Perspectives on Proof Systems and their Significance

May 3, 2012 – ENS, 45 rue d'Ulm 75005 Paris

Salle de séminaire du Cirphles, Département de Philosophie (sous-sol du pavillon Pasteur)




Workshop on Hypothetical Reasoning

Date: 16-17 April 2012
Location: Universität Tübingen, Wilhelm-Schickard-Institut, Sand 6, Room F116


Monday, 16 April 2012, 10.30-17.30:

  • Alberto Naibo & Mattia Petrolo (Paris): Towards a verificationist account of classical propositional logic
  • Luca Tranchini (Tübingen): How to Tarski Dummett-Prawitz's validity
  • Thomas Piecha (Tübingen): Atomic systems and constructive semantics
  • Jean-Baptiste Joinet (Paris): Motivated hypothesis: On the Colson & Michel approach of hypothetical reasoning
  • Jean Fichot (Paris): Proofs and counterexamples

Tuesday, 17 April 2012, 9.00-13.30:

  • Peter Schroeder-Heister (Tübingen): Towards a calculus of squares – The proof-theoretic significance of the square of opposition
  • Rainer Lüdecke (Tübingen): A game semantics for normal logic programs
  • Ernst Zimmermann: Two extensions of natural deduction
  • Michael Arndt (Tübingen): Directionality in logical calculi
  • Rene Gazzari (Lissabon): The application of Lindenbaum's Theorem




June 8, 2010 – Ecole Normale Supérieure, 29 rue d'Ulm 75005 Paris

Morning: Salle de réunion du Pavillon Jardin

Afternoon: Salle Lapie - 1st Floor




Proofs and Meaning: Logical and Philosophical Perspectives

March 22, 2010 – Maison des sciences de l'homme, Salle 206, 54, Bd Raspail, 75006 Paris


  •  9h00 Opening of the Workshop
  •  9h15 Peter Schroeder-Heister (Universität Tübingen): Reflection and Symmetry for the Sequent Calculus
  • 10h15 Jean-Baptiste Joinet (Université Paris 1): Protological Foundations for Logic
  • 11h15 Coffee Break
  • 11h30 Noam Zeilberger (Université Paris 7): Symmetry and Asymmetry in the Logical Laws (Rereading Dummett through Girard)
  • 12h30 Lunch
  • 14h00 Göran Sundholm (University of Leiden): Do Logical Constants (and Logical Consequence) determine Logicality also from a Constructivist Point of View?
  • 15h00 Jean Fichot (IHPST): Proof-theoretic Semantics and Feasibility
  • 16h00 Coffee Break
  • 16h15 Alberto Naibo (Université Paris 1) & Mattia Petrolo (Université Paris 7): Logical Constants from a Computational Point of View
  • 17h15 Conclusion and final remarks



First Project Meeting

The first project meeting takes place on 24/25 November 2009 at the IHPST, Paris.
Special guest: Per Martin-Löf (Stockholm)


  • Introductory remarks by Michel Bourdeau and Peter Schroeder-Heister.

Presentations by:

Concluding note:

  • Per Martin-Löf: On the Notion of Hypothesis in Type Theory.