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 "constraint handling rules what else"):
  Abstract: Constraint Handling Rules (CHR) is both an effective concurrent declarative constraint-based programming language and a versatile computational formalism. While conceptually simple, CHR is distinguished by a remarkable combination of desirable features: - semantic foundation in classical and linear logic, - effective and efficient sequential and parallel execution model - guaranteed properties like the anytime online algorithm properties - powerful analysis methods for deciding essential program properties. This overview of CHR research and applications is by no complete. It concentrates on the years since 2000. Up-to-date information on CHR can be found at the CHR web-site www.constraint-handling-rules.org, including the slides of the keynote talk associated with this article, an extensive bibliography, online demo versions and free downloads of the language.

Includes members:
  Member "a complete and terminating execution model for constraint handling rules":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "on proving confluence modulo equivalence for constraint handling rules")
  Member "linear logic based analysis of constraint handling rules with disjunction":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "distance constraint satisfaction problems")
  Member "automatic generation of chr constraint solvers":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "linear logic based analysis of constraint handling rules with disjunction")

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.PL(Programming Languages)