Modal Logics for Model Change

Logic and Computation Courses

Advanced Course

Modal Logics for Model Change,
Raul Fervari (The National University of Córdoba, Argentina) and Fernando R. Velázquez-Quesada (University of Amsterdam, The Netherlands)

Week 2, 17:00 – 18:30, Room 224, Floor 1

Dynamic Epistemic Logic (DEL) has become a useful tool for describing changes in different systems and concepts, as shown by its analysis of the effect of different forms of communication (public, private) on the knowledge of a set of agents, or its study of the effect of social influence on an agent’s preferences/opinions. One of DEL‘s key features is that changes are not represented by means of transitions within a system (as done, e.g., in propositional dynamic logic), but rather as operations that change the whole model in which formulas are evaluated. Thus, DEL can be abstractly understood as the study of modal logics for model change. This course provides a technical discussion on different operations that can be performed over DEL (and, in general, modal logic)’s preferred models, relational ‘Kripke’ models.


Tentative outline (full details of the references can be found on the slides)

  1. Monday: relational models; removing worlds. Basic concepts of relational models and the basic modal language describing them (Blackburn et al. 2001). Operation for removing worlds (so called Public announcement logic; Plaza 1989, Gerbrandy and Groeneveld 1997). Slides.
  2. Tuesday: adding worlds. (i) Adding one world and adding a new evaluation point (Aucher et al. 2009); (ii) action models (Baltag et al. 1998, Baltag and Moss 2004). Slides.
  3. Wednesday: valuation change. (i) Simple assignments (van Ditmarsch et al. 2005); (ii) memory logics (Areces et al. 2011a,c, 2012b). Slides
  4. Thursday: relational change I. (i) Adding and removing edges (Aucher et al. 2009); (ii) relational change (van Benthem and Liu 2007, van Benthem 2007); (iii) transformers (van Benthem et al. 2006). Slides (part 1) (part 2).
  5. Friday: relational change II.(i) Sabotage logic (van Benthem 2005, Areces
    et al. 2015, Aucher et al. 2015); (ii) swap logic, bridge logic (Areces et al.
    2012a, 2014b,a, 2015, 2017). Slides