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 "a formal presentation of mongodb extended version"):
  Abstract: A significant number of database architectures and data models have been proposed during the last decade. While some of these new systems have gained in popularity, their formal semantics are generally still missing. In this paper, we consider the symptomatic case of MongoDB, a widely adopted document database, in which roughly speaking relational tables correspond to collections, and tuples to documents. We provide a formalization of the JSON-based data model adopted by MongoDB, and of a core fragment of the MongoDB aggregation query language, MUPGL, which includes the match, unwind, project, group, and lookup operators. We study the expressiveness of MUPGL by defining a relational view of MongoDB databases and developing a translation from relational algebra to MUPGL. Notably, we show that the MUPG fragment is already at least as expressive as full relational algebra over (the relational view of) a single collection, and in particular able to express arbitrary joins. We further investigate the computational complexity of MUPGL and of significant fragments of it.

Includes members:
  Member "the sql query language configurable unifying and semi structured":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "an lsm based tuple compaction framework for apache asterixdb")
  Member "static and dynamic semantics of nosql languages":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "verification of high level transformations with inductive refinement types")

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)