@inproceedings{OikarinenJ:LPNMR09, author = {Emilia Oikarinen and Matti J\"arvisalo}, booktitle = {Proceedings of the 10th International Conference on Logic Programming and Nonmonotonic Reasoning (LPNMR 2009)}, editor = {Esra Erdem and Fangzhen Lin and Torsten Schaub}, pages = {236--249}, publisher = {Springer}, series = {Lecture Notes in Computer Science}, title = {{Max-ASP}: Maximum Satisfiability of Answer Set Programs}, volume = {5753}, year = {2009}, } Abstract: This paper studies answer set programming (ASP) in the generalized context of soft constraints and optimization criteria. In analogy to the well-known Max-SAT problem of maximum satisfiability of propositional formulas, we introduce the problems of unweighted and weighted Max-ASP. Given a normal logic program , in Max-ASP the goal is to find so called optimal Max-ASP models, which minimize the total cost of unsatisfied rules in and are at the same time answer sets for the set of satisfied rules in . Inference rules for Max-ASP are developed, resulting in a complete branch-and-bound algorithm for finding optimal models for weighted Max-ASP instances. Differences between the Max-ASP problem and earlier proposed related concepts in the context of ASP are also discussed. Furthermore, translations between Max-ASP and Max-SAT are studied.