On January 31, we will have a LogiCIC/LIRa joint session with Janusz Czelakowski.
Everyone is cordially invited!
Speaker: Janusz Czelakowski (Opole University)
Title: Freedom and Enforcement in Action – Elements of Formal Action theory
Date and Time: January 31, 2013, 15:30-17:30
Venue: Science Park 904, Room C1.112
Stit semantics gives an account of action from a certain perspective: actions are seen not asoperations performed in an action system and yielding new states of affairs, but rather asselections of pre-existent histories (or trajectories) of the system in time. Stit semantics istherefore time oriented, and time, being a situational component of action, plays a special role in it. In the talk an approach to action theory which stems from formal linguistics anddynamic logic is presented. An elementary action system is a triple (*) (W, R, A), where W isa set of states, R is a binary relation on W called the transition relation between states, and Ais a non-empty family of binary relations on W. (*) is thus a multi-modal frame in which therelation R is distinguished. The members of A are called atomic actions of the system (*). Acompound action (over (*)) is a set of finite sequences of atomic actions from A. Everycompound action is thus viewed as a formal language over the alphabet A. In ordered actionsystems the set of states W is additionally partially ordered. A situational action system is anextension of an elementary action system which takes into account the situational envelope inwhich actions are immersed. A comparison with stit semantics is discussed. In the talk anapproach to deontic logic is presented according to which actions (or deeds), and not states ofaffairs, bear deontic values (as being obligatory, forbidden, permitted). The notion of anatomic norm and its relationship with the above interpretation of the deontic operators isdiscussed. The term norm receives a wider meaning than in jurisprudence and encompassesmoral norms, linguisitic norms, social norms – providing patterns of behaviour in socialcommunities, conventions, etiquettes etc. In our approach norms play a role similar to that ofrules of inference in logic (but the analogy is rather loose) – norms are rules of action; theyguide actions and determine circumstances under which some actions are permitted,forbidden or obligatory. To each atomic norm a certain normative proposition is assigned;norms however are not reducible to propositions.