Computing Weighted Solutions in Answer Set Programming

Abstract

Abstract. For some problems with many solutions, like planning and phylogeny reconstruction, one way to compute more desirable solutions is to assign weights to solutions, and then pick the ones whose weights are over (resp. below) a threshold. This paper studies computing weighted solutions to such problems in Answer Set Programming. We investigate two sorts of methods for computing weighted solutions: one suggests modifying the representation of the problem and the other suggests modifying the search procedure of the answer set solver. We show the applicability and the effectiveness of these methods in phylogeny reconstruction.

Computing weighted solutions in ASP: representation-based method vs. search-based method

“…For each problem, for each method, we present the computation time, the size of the ground program, and the size of the mem-ory used in computation. 3 For instance, let us consider computing a phylogeny with at most 17 incompatible characters, and whose weight is at least 45. With the representation-method, CLASP takes 15.32 CPU sec.s to compute such a phylogeny; the ground program has 79229 atoms and 1585419 rules; the computation of the phylogeny consumes 369 MB of memory.…”

“…This paper extends [3] by a detailed discussion on the representation-based method and the search-based method for computing weighted solutions as well as a discussion on computing similar/diverse weighted solutions. It also extends the discussion of experimental results.…”

PHYLO-ASP: Phylogenetic Systematics with Answer Set Programming

“…We have discussed the applicability and effectiveness of PHYLO-ASP with three sets of taxa: Indo-European languages, Chinese dialects, and Alcatenia species. Our ongoing work involves extending PHYLO-ASP to analyze and compare phylogenetic trees and networks [18,19].…”