Pushing the Limits of Clingo’s Incremental Grounding and Solving Capabilities in Practical Applications

Abstract

Incremental techniques aim at making it possible to improve the performance of the grounding and solving processes by reusing the results of previous executions. Clingo supports both incremental grounding and incremental solving computations. In order to leverage incremental computations in clingo, the incremental fragments of ASP programs must satisfy certain safety-related conditions. In a number of problem domains and reasoning tasks, these conditions can be satisfied in a fairly straightforward way. However, we have observed that in certain practical applications, satisfying the conditions becomes more challenging, to the point that it is sometimes unclear how or even if it is possible to leverage incremental computations. In this paper, we report our findings, and ultimate success, with the use of incremental grounding and solving techniques in one of these challenging cases. We describe the domain, which is linked to a large practical application, discuss the challenges we faced in attempting to leverage incremental computations, and then describe the techniques that we developed, in particular at the level of methods for encoding the domain knowledge and of algorithms supporting the intended interleaving of grounding and solving. We believe that our findings may provide valuable information to practitioners facing similar challenges and ultimately increase the adoption of clingo’s incremental capabilities for complex practical applications.