A paraconsistent approach to actions in informationally complex environments

Abstract

Contemporary systems situated in real-world open environments frequently have to cope with incomplete and inconsistent information that typically increases complexity of reasoning and decision processes. Realistic modeling of such informationally complex environments calls for nuanced tools. In particular, incomplete and inconsistent information should neither trivialize nor stop both reasoning or planning. The paper introduces ACT-LOG, a rule-based four-valued language designed to specify actions in a paraconsistent and paracomplete manner. ACTLOG is an extension of 4QL Bel , a language for reasoning with paraconsistent belief bases. Each belief base stores multiple world representations. In this context, ACTLOG's action may be seen as a belief bases' transformer. In contrast to other approaches, ACTLOG actions can be executed even when the underlying belief base contents is inconsistent and/or partial. ACTLOG provides a nuanced action specification tools, allowing for subtle interplay among various forms of nonmonotonic, paraconsistent, paracomplete and doxastic reasoning methods applicable in informationally complex environments. Despite its rich modeling possibilities, it remains tractable. ACTLOG permits for composite actions by using sequential and parallel compositions as well as conditional specifications. The framework is illustrated on a decontamination case study known from the literature.

A Paraconsistent ASP-like Language with Tractable Model Generation

“…While the ontology may be huge, the inconsistency affects only literals involving ns(.). Some Further Use-Cases Due to a limited space let us only indicate some further use cases being directly relevant to the current paper: 3 actions in potentially inconsistent/incomplete environments [14]; belief fusion and shadowing [13,22]; argumentation [23,24]; approximate reasoning [59].…”

“…E.g., if the goal is important, like helping victims, a plan with inconsistent goal may be better than having no plan. For many further arguments towards paraconsistency see [1,3,10,11,12,13,14,20,17,24,57,61] and numerous references there.…”

“…Theorem 3. Let Π be an ASP program stratifiable with respect to the set of default literals D and Π ′ be a 4QL program obtained from Π by substituting default negations by inspection operators as in (14). Then the well supported model…”