human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "logics for unranked trees an overview"):
  Abstract: Labeled unranked trees are used as a model of XML documents, and logical#N#languages for them have been studied actively over the past several years. Such#N#logics have different purposes: some are better suited for extracting data,#N#some for expressing navigational properties, and some make it easy to relate#N#complex properties of trees to the existence of tree automata for those#N#properties. Furthermore, logics differ significantly in their model-checking#N#properties, their automata models, and their behavior on ordered and unordered#N#trees. In this paper we present a survey of logics for unranked trees.

Includes members:
  Member "conjunctive queries over trees":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "conjunctive queries on probabilistic graphs combined complexity")
  Member "on the complexity of nonrecursive xquery and functional query languages on complex values":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "incremental view maintenance for collection programming")
  Member "tight lower bounds for query processing on streaming and external memory data":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "streamability of nested word transductions")
  Member "monadic datalog and the expressive power of languages for web information extraction":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "monadic datalog containment on trees using the descendant axis")

Question: Please tell me which class the source paper 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)