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: "decidability complexity and expressiveness of first order logic over the subword ordering"
  Abstract: We consider first-order logic over the subword ordering on finite words, where each word is available as a constant. Our first result is that the $\Sigma_1$ theory is undecidable (already over two letters). #R##N#We investigate the decidability border by considering fragments where all but a certain number of variables are alternation bounded, meaning that the variable must always be quantified over languages with a bounded number of letter alternations. We prove that when at most two variables are not alternation bounded, the $\Sigma_1$ fragment is decidable, and that it becomes undecidable when three variables are not alternation bounded. Regarding higher quantifier alternation depths, we prove that the $\Sigma_2$ fragment is undecidable already for one variable without alternation bound and that when all variables are alternation bounded, the entire first-order theory is decidable.

Connected through hyperedge HE-1 (induced by source paper "scattered factor universality of words"):
  with members:
    - "k spectra of weakly c balanced words"
    - "languages ordered by the subword order"
    - "computing the k binomial complexity of the thue morse word"
    - "testing simon s congruence"
    - "multivariate fine grained complexity of longest common subsequence"
    - "complexity of universality and related problems for partially ordered nfas"
    - "the complexity of downward closure comparisons"
    - "on the index of simon s congruence for piecewise testability"

Connected through hyperedge HE-2 (induced by source paper "the theory of concatenation over finite models"):
  with members:
    - "dynamic complexity of document spanners"
    - "matching patterns with variables"
    - "weight annotation in information extraction"
    - "constant delay enumeration for nondeterministic document spanners"
    - "split correctness in information extraction"
    - "deterministic regular expressions with back references"
    - "constant delay algorithms for regular document spanners"
    - "the hardness of solving simple word equations"

Connected through hyperedge HE-3 (induced by source paper "matching patterns with variables"):
  with members:
    - "graph and string parameters connections between pathwidth cutwidth and the locality number"
    - "quadratic word equations with length constraints counter systems and presburger arithmetic with divisibility"
    - "the hardness of solving simple word equations"
    - "the runs theorem"
    - "detecting one variable patterns"
    - "solutions of word equations over partially commutative structures"
    - "a parameterized study of maximum generalized pattern matching problems"
    - "searching of gapped repeats and subrepetitions in a word"

Connected through hyperedge HE-4 (induced by source paper "languages ordered by the subword order"):
  with members:
    - "defining recursive predicates in graph orders"
    - "decidability in the logic of subsequences and supersequences"
    - "the height of piecewise testable languages with applications in logical complexity"
    - "arithmetic first order logic and counting quantifiers"

Connected through hyperedge HE-5 (induced by source paper "on shuffle products acyclic automata and piecewise testable languages"):
  with members:
    - "piecewise testable languages and nondeterministic automata"
    - "the height of piecewise testable languages and the complexity of the logic of subwords"
    - "the height of piecewise testable languages with applications in logical complexity"

Connected through hyperedge HE-6 (induced by source paper "k spectra of weakly c balanced words"):
  with members:
    - "the complexity of downward closure comparisons"

Connected through hyperedge HE-7 (induced by source paper "the satisfiability of extended word equations the boundary between decidability and undecidability"):
  with members:
    - "recompression a simple and powerful technique for word equations"

Connected through hyperedge HE-8 (induced by source paper "defining recursive predicates in graph orders"):
  with members:
    - "decidability in the logic of subsequences and supersequences"

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)