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: "two way unary temporal logic over trees"
  Abstract: We consider a temporal logic EF+F^-1 for unranked, unordered finite trees.#N#The logic has two operators: EF\phi, which says "in some proper descendant \phi#N#holds", and F^-1\phi, which says "in some proper ancestor \phi holds". We#N#present an algorithm for deciding if a regular language of unranked finite#N#trees can be expressed in EF+F^-1. The algorithm uses a characterization#N#expressed in terms of forest algebras.

Connected through hyperedge HE-1 (induced by source paper "deciding definability in fo2 h v on trees"):
  with members:
    - "piecewise testable tree languages"
    - "wreath products of forest algebras with applications to tree logics"
    - "a decidable characterization of locally testable tree languages"
    - "tree languages defined in first order logic with one quantifier alternation"

Connected through hyperedge HE-2 (induced by source paper "wreath products of forest algebras with applications to tree logics"):
  with members:
    - "piecewise testable tree languages"
    - "a decidable characterization of locally testable tree languages"
    - "tree languages defined in first order logic with one quantifier alternation"
    - "logics for unranked trees an overview"
    - "algebraic recognizability of regular tree languages"

Connected through hyperedge HE-3 (induced by source paper "piecewise testable tree languages"):
  with members:
    - "wreath products of forest algebras with applications to tree logics"

Connected through hyperedge HE-4 (induced by source paper "a decidable characterization of locally testable tree languages"):
  with members:
    - "piecewise testable tree languages"
    - "tree languages defined in first order logic with one quantifier alternation"
    - "algebraic recognizability of regular tree languages"

Connected through hyperedge HE-5 (induced by source paper "tree languages defined in first order logic with one quantifier alternation"):
  with members:
    - "piecewise testable tree languages"

Connected through hyperedge HE-6 (induced by source paper "fragments of first order logic over infinite words"):
  with members:
    - "piecewise testable tree languages"
    - "tree languages defined in first order logic with one quantifier alternation"
    - "logic meets algebra the case of regular languages"
    - "algebraic recognizability of languages"

Connected through hyperedge HE-7 (induced by source paper "algebraic characterization of logically defined tree languages"):
  with members:
    - "piecewise testable tree languages"
    - "tree languages defined in first order logic with one quantifier alternation"
    - "algebraic recognizability of languages"
    - "algebraic recognizability of regular tree languages"

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)