Modeling Normative Multi-Agent Systems from a Kelsenian Perspective.

Standard Deontic Logic (SDL) has been used as the underlying logic to model and reason over Multi-Agent Systems governed by norms (NorMAS). It is known that SDL is not able to represent contrary-to-duty (CTD) scenarios in a consistent way. That is the case, for example, of the so-called Chisholm paradox, which models a situation in which a conditional obligation that specifies what must be done when a primary obligation is violated holds. In SDL, the set of sentences that represent the Chisholm paradox derives inconsistent sentences. Due to the autonomy of the software agents of a NorMAS, norms may be violated and the underlying logic used to model the NorMAS should be able to represent violation scenarios. The contribution of this paper is threefold: (i) we present how Kelsenian thinking, from his jurisprudence in the context of legal ontologies, and Intuitionist Hybrid Logic can be adopted in the modeling of NorMAS, (ii) discuss how this approach overcomes limitations of the SDL and (iii) present a discussion about normative conflict identification according to Hill's functional taxonomy, that generalizes from standard identification by impossibility-of-joint-compliance test.