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: "abstract diagnosis for timed concurrent constraint programs"
  Abstract: The Timed Concurrent Constraint Language (tccp in short) is a concurrent logic language based on the simple but powerful concurrent constraint paradigm of Saraswat. In this paradigm, the notion of store-as-value is replaced by the notion of store-as-constraint, which introduces some differences w.r.t. other approaches to concurrency. In this paper, we provide a general framework for the debugging of tccp programs. To this end, we first present a new compact, bottom-up semantics for the language that is well suited for debugging and verification purposes in the context of reactive systems. We also provide an abstract semantics that allows us to effectively implement debugging algorithms based on abstract interpretation. Given a tccp program and a behavior specification, our debugging approach automatically detects whether the program satisfies the specification. This differs from other semiautomatic approaches to debugging and avoids the need to provide symptoms in advance. We show the efficacy of our approach by introducing two illustrative examples. We choose a specific abstract domain and show how we can detect that a program is erroneous.

Connected through hyperedge HE-1 (induced by source paper "an assertion language for slicing constraint logic languages"):
  with members:
    - "slicing concurrent constraint programs"
    - "abstract interpretation of temporal concurrent constraint programs"

Connected through hyperedge HE-2 (induced by source paper "a simulation tool for tccp programs"):
  with members:
    - "modeling hybrid systems in the concurrent constraint paradigm"

Connected through hyperedge HE-3 (induced by source paper "slicing concurrent constraint programs"):
  with members:
    - "abstract interpretation of temporal concurrent constraint programs"
    - "a logical framework for systems biology"

Connected through hyperedge HE-4 (induced by source paper "abstract interpretation of temporal concurrent constraint programs"):
  with members:
    - "state space reduction in the maude nrl protocol analyzer"
    - "towards a unified framework for declarative structured communications"
    - "automatic verification of timed concurrent constraint programs"

Connected through hyperedge HE-5 (induced by source paper "abstract diagnosis for tccp using a linear temporal logic"):
  with members:
    - "towards an effective decision procedure for ltl formulas with constraints"
    - "automatic verification of timed concurrent constraint programs"

Connected through hyperedge HE-6 (induced by source paper "tcc with history"):
  with members:
    - "focusing and polarization in intuitionistic logic"

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)