LogiCIC/LIRa Session: Valentin Goranko and Daisuke Bekki

On October 17, we will have a long LogiCIC/LIRa joint session with two talks by Valentin Goranko and Daisuke Bekki.

Please note that the two talks will be on a WEDNESDAY at 15:00 and that this seminar session is separate from the LogiCIC tutorial which Valentin Goranko will teach on the same week (more info about the tutorial can be found here).

Date: Wednesday, October 17, 2012, 15:00–18:00
Venue: Science Park 904, Room A1.04

Speaker: Daisuke Bekki (Ochanomizu University)
Title: Dependent type semantics: the framework
This talk introduces dependent type semantics, a new framework of natural language semantics based on dependent type theory. Main features of dependent type semantics are the following:
1) it is dynamic: it analyzes E-type/donkey anaphora with well-formed representations.
2) it is proof-theoretic: entailments between the representations can be calculated without recourse to their models.
3) it is compositional: the semantic representations of sentences are derived from the lexicalized representations by a fixed number of combinatory rules.
4) it explains accessibility: accessibility/inaccessibility of anaphora is reduced to the structural differences between proofs.
These are achieved by a specific way of combining type theoretical approaches (cf. Ranta (1994)) and the continuation-based approaches (cf. de Groote (2006)) to dynamic binding.  From the perspective of dependent type semantics, the source of dynamics in natural language is the dependence on proofs of the preceding discourses.

Speaker: Valentin Goranko (Technical University of Denmark)
Title: Modeling the Dynamics of Information and Abilities of Players inMulti-Player Games
I will discuss an early work towards a realistic treatment and logical formalization of the abilities of players to achieve objectives in multi-player games under incomplete, imperfect, or simply uncertain information that they may have about the game and about the course of the play. In this talk, after some motivating examples I will introduce a modeling framework for capturing the interplay between the dynamics of information and the dynamics of abilities of players. This framework takes into account both the a priori information of players with respect to the game structure and the empirical information that players develop over the course of an actual play. It associate with them respective information relations and notions of `a priori’ and `empirical’ strategies and strategic abilities. The empirical information relations are updated in the course of the play by a mechanism similar to the model update mechanism applied in Dynamic Epistemic Logic (DEL). Lastly, I will introduce a variation of the multi-agent logic ATL with incomplete information to formalize the reasoning in this framework and will briefly discuss the conceptual problem of model checking in that new logic under different assumptions about the abilities of the players to observe, remember, and reason.