Back to first pageBack to first page Centre for Artificial Intelligence of UNL
Browse our site

DiFoS - Dialogical Foundations of Semantics

Project information

Collaborative Research Project within the EUROCORES programme "LogiCCC" of the European Science Foundation (ESF)
Principal Investigators of the DiFoS project:

Peter Schroeder-Heister (Tübingen)
Reinhard Kahle (Lisbon)
Benedikt Löwe (Amsterdam)

The project work will start in autumn 2008.
Project titles of other projects within LogiCCC:

* Logic for Interaction (LINT)
* The Logic of Causal and Probabilistic Reasoning in Uncertain Environments (LcpR)
* Logical Models of Reasoning with Vague Information (LoMoReVi)
* Games for Analysis and Synthesis of Interactive Computational Systems (GASICS)
* Vagueness, Approximation, and Granularity (VAAG)
* Computational Foundations of Social Choice (CFSC)
* SOCIAL SOFTWARE for elections, the allocation of tenders and coalition/alliance formation (SSEAC)

(links will be inserted as soon as all project pages have been set up)
Preliminary description of the DiFoS project:

Incorporating interaction into the traditionally static picture of logic is one of the most vital and fascinating topics in current logical research. The broad research area of "Logic and Games" deals with reasoning about games, but also with the use of games in reasoning, Looking at the current preoccupation of researchers with interaction in logic, it is easy to forget that the use of dialogues in logic goes back at least to Lorenzen's 1958 paper "Logik und Agon", and has its roots in much older traditions, going back to the pre-Socratics.

Our project aims to (1) describe the foundational value of Lorenzen's dialogical logic, and (2) embed it into a modern scientific context taking into account its historical roots.

(1) The foundational investigations consist in (i) discussing and clarifying technical points of dialogue semantics, and (ii) evaluating its philosophical background claims as well as its potential to lay the foundations for logical reasoning in mathematics, computer science and linguistics. These foundational investigations are the heart of the project and will be carried out in the form of two Master Projects, which are not assigned to a particular site, but are central projects which all three principal investigators are jointly committed to.

(2) The embedding into a modern context and the historical roots are subjects of several collaborative projects between two sites each, as well as of individual local projects. They investigate the role of negation and of definitional reasoning as paradigms for reasoning in general, the use of dialogues in informal and semi-formal mathematical proofs, the use of zero-knowledge proofs and extended logic programs in computer science, and of dialogical versions of the propositions-as-types approach within linguistics. Concerning the historical roots we concentrate, besides studying the modern history of dialogical logic, on medieval theories of obligationes.

Started in March 1st 2009 and was concluded in February 28 2013.


Participating entities: Universität Tübingen, Universiteit van Amsterdam.

Principal researchers: Peter Schroeder-Heister, Benedikt Löwe.

Researcher: Isabel Oitavem .


Funding entity: Fundação Ciência e Tecnologia (MCTES).

Reference: LogICCC/0001/2007

Funding: 43.200,00.


Principal researcher: Reinhard Kahle.

Researchers: Francisco Azevedo, Gregory Wheeler, João Leite, Luís Moniz Pereira, Jesse Alama.

Funding: 43.200,00.

Other information

Project website

Centre for Artificial Intelligence of UNL
Departamento de Informática, FCT/UNL
Quinta da Torre 2829-516 CAPARICA - Portugal
Tel. (+351) 21 294 8536 FAX (+351) 21 294 8541