Non-classical Logical Models of Information Dynamics

About the project

Dynamic logics such as versions of Propositional Dynamic Logic (PDL), Public Announcement Logic (PAL), and various logics of soft information update are well known logical models of phenomena involving change of the information available to agents such as humans, databases or computer programs. Change of information relates to dynamics of questions resolved on the basis of the information, a phenomenon formalized by dynamic logics of questions. All these models are based on classical logic, which entails a number of limitations (monotonicity, closure under classical consequence, inconsistency intolerance).

This project explores dynamic logics based on a family of non-classical logics, known as substructural logics, and their applications in modelling information dynamics. Firstly, the project focuses on internal non-classical models of information dynamics, that is, non-classical logics characterized by models with accessibility relations that express change of information. These can be binary relations in the style of PDL, or ternary relations in the style of the relational semantics for substructural logics. Secondly, the project focuses on external non-classical models of information dynamics, that is, extensions of non-classical logics with modalities pertaining to transformations of models in the style of dynamic epistemic logic.

The project was based at the Institute of Computer Science of the Czech Academy of Sciences and funded by the Czech Science Foundation, grant no. 18-19162Y. It run from January 2018 till June 2021.

The project team

Igor Sedlár (principal investigator)

Vít Punčochář

Andrew Tedder


Generalizations of PDL. We obtained general completeness and decidability results on versions of PDL based on substructural, many-valued and inquisitive logics; see [J1], [J2], [C3] and [C7] below.

Information dynamics in non-classical logics. We provided a number of information-dynamic interpretations and extensions of various non-classical logics, including the Lambek calculus [C2, J3], weak relevant logics [J4], and paraconsistent epistemic logic [C1].

Generalizations of PAL. We established a completeness result on non-classical inquisitive PAL [C4], with preparatory results on non-classical inquisitive epistemic logic [J5]. We studied epistemic updates in the context of Kripke semantics of intuitionistic and relevant logics in [C5], adding common knowledge to the framework and studying the relationship to the inquisitive framwork of [C4] in [C6].

(This list will be updated.)


Papers in journals:

Papers in conference proceedings:

Other publications:

  • M. A. Martins, I. Sedlár: Dynamic Logic. New Trends and Applications. Third International Workshop, DaLí 2020, Prague, Czech Republic, October 9–10, 2020, Revised Selected Papers. Volume 12569 of Lecture Notes in Computer Science. Springer, 2020.

Presentations (incomplete list)