human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "lpopt a rule optimization tool for answer set programming"
  Abstract: State-of-the-art answer set programming (ASP) solvers rely on a program called a grounder to convert non-ground programs containing variables into variable-free, propositional programs. The size of this grounding depends heavily on the size of the non-ground rules, and thus, reducing the size of such rules is a promising approach to improve solving performance. To this end, in this paper we announce lpopt, a tool that decomposes large logic programming rules into smaller rules that are easier to handle for current solvers. The tool is specifically tailored to handle the standard syntax of the ASP language (ASP-Core) and makes it easier for users to write efficient and intuitive ASP programs, which would otherwise often require significant hand-tuning by expert ASP engineers. It is based on an idea proposed by Morak and Woltran (2012) that we extend significantly in order to handle the full ASP syntax, including complex constructs like aggregates, weak constraints, and arithmetic expressions. We present the algorithm, the theoretical foundations on how to treat these constructs, as well as an experimental evaluation showing the viability of our approach.

Connected through hyperedge HE-1 (induced by source paper "selp a single shot epistemic logic program solver"):
  with members:
    - "a survey of advances in epistemic logic program solvers"
    - "multi shot asp solving with clingo"
    - "the power of non ground rules in answer set programming"
    - "a parallel memory efficient epistemic logic program solver harder better faster"
    - "clingo asp control preliminary report"
    - "revisiting epistemic specifications"
    - "well founded and stable semantics of logic programs with aggregates"

Connected through hyperedge HE-2 (induced by source paper "solving advanced argumentation problems with answer set programming"):
  with members:
    - "depqbf 6 0 a search based qbf solver beyond traditional qcdcl"
    - "the power of non ground rules in answer set programming"
    - "stable unstable semantics beyond np with normal logic programs"
    - "extension based semantics of abstract dialectical frameworks"
    - "the dlv system for knowledge representation and reasoning"

Connected through hyperedge HE-3 (induced by source paper "strong equivalence and program s structure in arguing essential equivalence between logic programs"):
  with members:
    - "abstract gringo"
    - "first order modular logic programs and their conservative extensions"
    - "modularity aspects of disjunctive stable models"
    - "a common view on strong uniform and other notions of equivalence in answer set programming"
    - "weight constraints as nested expressions"

Connected through hyperedge HE-4 (induced by source paper "encoding selection for solving hamiltonian cycle problems with asp"):
  with members:
    - "automated algorithm selection survey and perspectives"
    - "a multi engine approach to answer set programming"
    - "claspfolio 2 advances in algorithm selection for answer set programming"
    - "satzilla portfolio based algorithm selection for sat"
    - "the dlv system for knowledge representation and reasoning"

Connected through hyperedge HE-5 (induced by source paper "optimizing answer set computation via heuristic based decomposition"):
  with members:
    - "the power of non ground rules in answer set programming"
    - "asperix a first order forward chaining approach for answer set computing"
    - "clingo asp control preliminary report"
    - "parallel instantiation of asp programs techniques and experiments"
    - "the dlv system for knowledge representation and reasoning"
    - "unfolding partiality and disjunctions in stable model semantics"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.LO(Logic in Computer Science)