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 complexity of aggregates over extractions by regular expressions"):
  Abstract: Regular expressions with capture variables, also known as "regex formulas," extract relations of spans (intervals identified by their start and end indices) from text. Based on these Fagin et al. introduced regular document spanners which are the closure of regex formulas under Relational Algebra. In this work, we study the computational complexity of querying text by aggregate functions, like sum, average or quantiles, on top of regular document spanners. To this end, we formally define aggregate functions over regular document spanners and analyze the computational complexity of exact and approximative computation of the aggregates. To be precise, we show that in a restricted case all aggregates can be computed in polynomial time. In general, however, even though exact computation is intractable, some aggregates can still be approximated with fully polynomial-time randomized approximation schemes (FPRAS).

Includes members:
  Member "complexity bounds for relational algebra over document spanners":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "grammars for document spanenrs")
  Member "constant delay enumeration for nondeterministic document spanners":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "grammars for document spanenrs")
  Member "constant delay algorithms for regular document spanners":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "grammars for document spanenrs")
  Member "joining extractions of regular expressions":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "grammars for document spanenrs")

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.DB(Databases)