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 "the satisfiability of extended word equations the boundary between decidability and undecidability"):
  Abstract: The study of word equations (or the existential theory of equations over free monoids) is a central topic in mathematics and theoretical computer science. The problem of deciding whether a given word equation has a solution was shown to be decidable by Makanin in the late 1970s, and since then considerable work has been done on this topic. In recent years, this decidability question has gained critical importance in the context of string SMT solvers for security analysis. Further, many extensions (e.g., quantifier-free word equations with linear arithmetic over the length function) and fragments (e.g., restrictions on the number of variables) of this theory are important from a theoretical point of view, as well as for program analysis applications. Motivated by these considerations, we prove several new results and thus shed light on the boundary between decidability and undecidability for many fragments and extensions of the first order theory of word equations.

Includes members:
  Member "decidability complexity and expressiveness of first order logic over the subword ordering":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "scattered factor universality of words")
  Member "recompression a simple and powerful technique for word equations":
    also connected through other hyperedges:
      - Hyperedge HE-2 (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)