FLINGO -- Instilling ASP Expressiveness into Linear Integer Constraints

TL;DR

FLINGO introduces a novel language that integrates ASP expressiveness into linear integer constraints, enabling more flexible and expressive constraint answer set programming.

Contribution

The paper presents FLINGO, a new language and tool that embed ASP-like features into numerical constraints, enhancing CASP expressiveness and compatibility with existing formats.

Findings

FLINGO allows default values and non-deterministic assignments within constraints.

The translation from FLINGO to standard CASP programs is established.

Examples demonstrate FLINGO's enhanced expressiveness.

Abstract

Constraint Answer Set Programming (CASP) is a hybrid paradigm that enriches Answer Set Programming (ASP) with numerical constraint processing, something required in many real-world applications. The usual specification of constraints in most CASP solvers is closer to the numerical back-end expressiveness and semantics, rather than to standard specification in ASP. In the latter, numerical attributes are represented with predicates and this allows declaring default values, leaving the attribute undefined, making non-deterministic assignments with choice rules or using aggregated values. In CASP, most (if not all) of these features are lost once we switch to a constraint-based representation of those same attributes. In this paper, we present the FLINGO language (and tool) that incorporates the aforementioned expressiveness inside the numerical constraints and we illustrate its use with several examples. Based on previous work that established its semantic foundations, we also present a translation from the newly introduced FLINGO syntax to regular CASP programs following the CLINGCON input format.