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: "computing small unsatisfiable cores in satisfiability modulo theories"
  Abstract: The problem of finding small unsatisfiable cores for SAT formulas has recently received a lot of interest, mostly for its applications in formal verification. However, propositional logic is often not expressive enough for representing many interesting verification problems, which can be more naturally addressed in the framework of Satisfiability Modulo Theories, SMT. Surprisingly, the problem of finding unsatisfiable cores in SMT has received very little attention in the literature.#R##N##R##N#In this paper we present a novel approach to this problem, called the Lemma-Lifting approach. The main idea is to combine an SMT solver with an external propositional core extractor. The SMT solver produces the theory lemmas found during the search, dynamically lifting the suitable amount of theory information to the Boolean level. The core extractor is then called on the Boolean abstraction of the original SMT problem and of the theory lemmas. This results in an unsatisfiable core for the original SMT problem, once the remaining theory lemmas are removed.#R##N##R##N#The approach is conceptually interesting, and has several advantages in practice. In fact, it is extremely simple to implement and to update, and it can be interfaced with every propositional core extractor in a plug-and-play manner, so as to benefit for free of all unsat-core reduction techniques which have been or will be made available.#R##N##R##N#We have evaluated our algorithm with a very extensive empirical test on SMT-LIB benchmarks, which confirms the validity and potential of this approach.

Connected through hyperedge HE-1 (induced by source paper "multi objective reasoning with constrained goal models"):
  with members:
    - "requirements evolution and evolution requirements with constrained goal models"
    - "optimization modulo theories with linear rational costs"
    - "pushing the envelope of optimization modulo theories with linear arithmetic cost functions"
    - "optimization in smt with la q cost functions"
    - "revisiting the core ontology and problem in requirements engineering"
    - "a new general method to generate random modal formulae for testing decision procedures"

Connected through hyperedge HE-2 (induced by source paper "extracting unsatisfiable cores for ltl via temporal resolution"):
  with members:
    - "computing minimal sets on propositional formulae i problems reductions"
    - "resolution proof transformation for compression and interpolation"
    - "enhancing unsatisfiable cores for ltl with information on temporal relevance"
    - "on the complexity of computing minimal unsatisfiable ltl formulas"
    - "handling conflicts in depth first search for ltl tableau to debug compliance based languages"
    - "linear encodings of bounded ltl model checking"
    - "clausal temporal resolution"

Connected through hyperedge HE-3 (induced by source paper "optimization modulo theories with linear rational costs"):
  with members:
    - "ilp modulo theories"
    - "optimization in smt with la q cost functions"
    - "efficient generation of craig interpolants in satisfiability modulo theories"

Connected through hyperedge HE-4 (induced by source paper "enhancing unsatisfiable cores for ltl with information on temporal relevance"):
  with members:
    - "extracting unsatisfiable cores for ltl via temporal resolution"
    - "a fully automatic problem solver with human style output"
    - "on the complexity of computing minimal unsatisfiable ltl formulas"
    - "handling conflicts in depth first search for ltl tableau to debug compliance based languages"
    - "clausal temporal resolution"

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)