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: "sound regular expression semantics for dynamic symbolic execution of javascript"
  Abstract: Existing support for regular expressions in automated test generation or verification tools is lacking. Common aspects of regular expression engines found in mainstream programming languages, such as backreferences or greedy matching, are commonly ignored or imprecisely approximated, leading to poor test coverage or failed proofs. In this paper, we present the first complete strategy to faithfully reason about regular expressions in the context of symbolic execution, focusing on the operators found in JavaScript. We model regular expression operations using string constraints and classical regular expressions and use a refinement scheme to address the problem of matching precedence and greediness. Our survey of over 400,000 JavaScript packages from the NPM software repository shows that one fifth make use of complex regular expressions features. We implemented our model in a dynamic symbolic execution engine for JavaScript and evaluated it on over 1,000 Node.js packages containing regular expressions, demonstrating that the strategy is effective and can increase line coverage of programs by up to 30%

Connected through hyperedge HE-1 (induced by source paper "a survey on string constraint solving"):
  with members:
    - "what is decidable about string constraints with the replaceall function"
    - "undecidability of a theory of strings linear arithmetic over length and string number conversion"
    - "a solver for a theory of strings and bit vectors"
    - "minizinc with strings"
    - "regular combinators for string transformations"
    - "approximation of grammar based compression via recompression"
    - "recompression a simple and powerful technique for word equations"
    - "algorithm selection for combinatorial search problems a survey"

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.PL(Programming Languages)