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 "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.

Includes members:
  Member "on the state complexity of closures and interiors of regular languages with subwords and superwords":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "well quasiorders and hierarchy theory")
  Member "decidability in the logic of subsequences and supersequences":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "languages ordered by the subword order")
  Member "generalized post embedding problems":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "well quasiorders and hierarchy theory")
  Member "the height of piecewise testable languages with applications in logical complexity":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "scattered factor universality of words")
  Member "subclasses of presburger arithmetic and the weak exp hierarchy":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "succinct population protocols for presburger arithmetic")
  Member "the power of priority channel systems":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "the ideal approach to computing closed subsets in well quasi orderings")
  Member "recompression a simple and powerful technique for word equations":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "a survey on string constraint solving")

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)