A Dynamic Preference Logic for Reasoning about Agent Programming

Abstract

In this work, we investigate the use of Dynamic Preference Logic to encode BDI mental attitudes. Further, exploring this codification and the representation of preferences over possible worlds by preferences over propositional formulas, here called priority graphs, we comment on how to interpret BDI agent programs in this logic. Also, using the connection between dynamic operations defined over preference models and their encoding as transformations on priority graphs, we show how our logic can be used not only to reason about agent programs, but as a tool to specify reasoning mechanisms to guarantee certain properties in the theory of rationality for the programming language.

Dynamic Preference Logic meets Iterated Belief Change: Representation Results and Postulates Characterization

“…We point out that in this work, we choose to employ our preference models as opposed to Grove's Systems of Spheres to study belief and its changes. The reason for this is that, firstly, preference-like models are more general structures and have been extensively studied as models for non-monotonic reasoning, conditional logics, and mental attitudes, as variant notions of belief [17,18,19,20,21,8]. By employing these models to study belief change operators, we may generalise our results and the insights obtained with our study to change operations for other mental attitudes and diverse dynamic phenomena.…”

“…Notice that, while DDL could, in principle, be used as a foundation for our study, this logic is less expressive than DPL. Also, by choosing to employ DPL instead of DDL as a foundational logic, our work can be connected to the work representing different mental attitudes in this logic [34,21,20] allowing the application of theoretically founded dynamic operators to dynamic phenomena for different mental attitudes.…”

“…A question that may arise from our work is whether the generalisation of Belief Change postulates from the semantic framework of Grove's systems of spheres to preference models is relevant from an epistemological point of view. We point out both that preference models have been extensively studied as models for non-monotonic reasoning and conditional logics [17,18,48] and to model different mental attitudes, such as Preferences [11,19], Goals and Desires [20], and Obligations [21], and different notions of Belief [8].…”

Tractable Reasoning about Agent Programming in Dynamic Preference Logic

“…An important result about the dynamified logic is that, if we consider some special kind of model, which includes the models we will use in Section III to reason about Agent Programming, it has the same expressibility as the static logic presented before [2]. In fact, the formulas [!ϕ]ψ, [⇑ ϕ]ψ and [⇓ ϕ]ψ, with ∈ {P, D}, are definable in the language L ≤P ,≤D (A) by a set of reduction axioms.…”

“…Recently, it has been proposed that Dynamic Preference Logic (DPL) can be used to reason about BDI Agent Programming with declarative mental attitudes [2], providing a. a computable two-way translation between specifications in the logic and agent programs. Reasoning in DPL is, however, not tractable in general.…”