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: "the covering problem"
  Abstract: An important endeavor in computer science is to understand the expressive#N#power of logical formalisms over discrete structures, such as words. Naturally,#N#"understanding" is not a mathematical notion. This investigation requires#N#therefore a concrete objective to capture this understanding. In the#N#literature, the standard choice for this objective is the membership problem,#N#whose aim is to find a procedure deciding whether an input regular language can#N#be defined in the logic under investigation. This approach was cemented as the#N#right one by the seminal work of Sch\"utzenberger, McNaughton and Papert on#N#first-order logic and has been in use since then. However, membership questions#N#are hard: for several important fragments, researchers have failed in this#N#endeavor despite decades of investigation. In view of recent results on one of#N#the most famous open questions, namely the quantifier alternation hierarchy of#N#first-order logic, an explanation may be that membership is too restrictive as#N#a setting. These new results were indeed obtained by considering more general#N#problems than membership, taking advantage of the increased flexibility of the#N#enriched mathematical setting. This opens a promising research avenue and#N#efforts have been devoted at identifying and solving such problems for natural#N#fragments. Until now however, these problems have been ad hoc, most fragments#N#relying on a specific one. A unique new problem replacing membership as the#N#right one is still missing. The main contribution of this paper is a suitable#N#candidate to play this role: the Covering Problem. We motivate this problem#N#with 3 arguments. First, it admits an elementary set theoretic formulation,#N#similar to membership. Second, we are able to reexplain or generalize all known#N#results with this problem. Third, we develop a mathematical framework and a#N#methodology tailored to the investigation of this problem.

Connected through hyperedge HE-1 (induced by source paper "partially ordered automata and piecewise testability"):
  with members:
    - "complexity of detectability opacity and a diagnosability for modular discrete event systems"
    - "complexity of universality and related problems for partially ordered nfas"
    - "separability by piecewise testable languages is ptime complete"
    - "complexity of deciding detectability in discrete event systems"
    - "piecewise testable languages and nondeterministic automata"
    - "the height of piecewise testable languages and the complexity of the logic of subwords"
    - "on separation by locally testable and locally threshold testable languages"
    - "separating regular languages by piecewise testable and unambiguous languages"

Connected through hyperedge HE-2 (induced by source paper "regular separability and intersection emptiness are independent problems"):
  with members:
    - "separation for dot depth two"
    - "regular separability of one counter automata"
    - "separating regular languages with first order logic"
    - "regular separability of parikh automata"
    - "separability of reachability sets of vector addition systems"
    - "unboundedness and downward closures of higher order pushdown automata"
    - "an approach to computing downward closures"
    - "a characterization for decidable separability by piecewise testable languages"

Connected through hyperedge HE-3 (induced by source paper "on all things star free"):
  with members:
    - "separation and covering for group based concatenation hierarchies"
    - "separation for dot depth two"
    - "generic results for concatenation hierarchies"
    - "separating regular languages with first order logic"
    - "characterizing classes of regular languages using prefix codes of bounded synchronization delay"
    - "going higher in the first order quantifier alternation hierarchy on words"

Connected through hyperedge HE-4 (induced by source paper "separation for dot depth two"):
  with members:
    - "generic results for concatenation hierarchies"
    - "separating regular languages with first order logic"
    - "going higher in the first order quantifier alternation hierarchy on words"
    - "separating regular languages by piecewise testable and unambiguous languages"
    - "efficient separability of regular languages by subsequences and suffixes"

Connected through hyperedge HE-5 (induced by source paper "separation and covering for group based concatenation hierarchies"):
  with members:
    - "separation for dot depth two"
    - "generic results for concatenation hierarchies"
    - "going higher in the first order quantifier alternation hierarchy on words"
    - "one quantifier alternation in first order logic with modular predicates"

Connected through hyperedge HE-6 (induced by source paper "covering and separation for logical fragments with modular predicates"):
  with members:
    - "separation for dot depth two"
    - "adding successor a transfer theorem for separation and covering"
    - "separating regular languages with first order logic"
    - "adding modular predicates to first order fragments"
    - "going higher in the first order quantifier alternation hierarchy on words"
    - "one quantifier alternation in first order logic with modular predicates"
    - "separating regular languages by piecewise testable and unambiguous languages"
    - "efficient separability of regular languages by subsequences and suffixes"

Connected through hyperedge HE-7 (induced by source paper "adding successor a transfer theorem for separation and covering"):
  with members:
    - "separating regular languages with two quantifier alternations"
    - "going higher in first order quantifier alternation hierarchies on words"
    - "separating regular languages with first order logic"
    - "quantifier alternation for infinite words"
    - "going higher in the first order quantifier alternation hierarchy on words"
    - "separating regular languages by piecewise testable and unambiguous languages"
    - "efficient separability of regular languages by subsequences and suffixes"
    - "around dot depth one"

Connected through hyperedge HE-8 (induced by source paper "generic results for concatenation hierarchies"):
  with members:
    - "separation for dot depth two"
    - "separating regular languages with two quantifier alternations"
    - "adding successor a transfer theorem for separation and covering"
    - "star height via games"
    - "going higher in first order quantifier alternation hierarchies on words"
    - "going higher in the first order quantifier alternation hierarchy on words"

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)