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: "modeling hybrid systems in the concurrent constraint paradigm"
  Abstract: Hybrid systems, which combine discrete and continuous dynamics, require quality modeling languages to be either described or analyzed. The Concurrent Constraint paradigm (ccp) is an expressive declarative paradigm, characterized by the use of a common constraint store to communicate and synchronize concurrent agents. In this paradigm, the information is stated in the form of constraints, in contrast to the variable/value style typical o f imperative languages. Several extensions of ccp have been proposed in order to model reactive systems. One of these extensions is the Timed Concurrent Constraint Language (tccp) that adds to ccp a notion of discrete time and new features to model time-out and preemption actions. The goal of this paper is to explore the expressive power of tccp to describe hybrid systems. We introduce the language Hy-tccp as a conservative extension of tccp, by adding a notion of continuous time and new constructs to describe the continuous dynamics of hybrid systems. In this paper, we present the syntax and the operational semantics of Hy-tccp together with some examples that show the expressive power of our new language.

Connected through hyperedge HE-1 (induced by source paper "a simulation tool for tccp programs"):
  with members:
    - "abstract diagnosis for timed concurrent constraint programs"

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)