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: "results and analysis of sygus comp 15"
  Abstract: Syntax-Guided Synthesis (SyGuS) is the computational problem of finding an implementation f that meets both a semantic constraint given by a logical formula $\varphi$ in a background theory T, and a syntactic constraint given by a grammar G, which specifies the allowed set of candidate implementations. Such a synthesis problem can be formally defined in SyGuS-IF, a language that is built on top of SMT-LIB. #R##N#The Syntax-Guided Synthesis Competition (SyGuS-comp) is an effort to facilitate, bring together and accelerate research and development of efficient solvers for SyGuS by providing a platform for evaluating different synthesis techniques on a comprehensive set of benchmarks. In this year's competition we added two specialized tracks: a track for conditional linear arithmetic, where the grammar need not be specified and is implicitly assumed to be that of the LIA logic of SMT-LIB, and a track for invariant synthesis problems, with special constructs conforming to the structure of an invariant synthesis problem. This paper presents and analyzes the results of SyGuS-comp'15.

Connected through hyperedge HE-1 (induced by source paper "oasis ilp guided synthesis of loop invariants"):
  with members:
    - "sygus comp 2017 results and analysis"

Connected through hyperedge HE-2 (induced by source paper "sygus comp 2017 results and analysis"):
  with members:
    - "sygus techniques in the core of an smt solver"
    - "language to specify syntax guided synthesis problems"

Connected through hyperedge HE-3 (induced by source paper "sygus techniques in the core of an smt solver"):
  with members:
    - "sygus comp 2016 results and analysis"
    - "smt based model checking for recursive programs"

Connected through hyperedge HE-4 (induced by source paper "using sygus to synthesize reactive motion plans"):
  with members:
    - "the first reactive synthesis competition syntcomp 2014"
    - "a high level ltl synthesis format tlsf v1 1 extended version"
    - "specification format for reactive synthesis problems"
    - "a multi paradigm language for reactive synthesis"
    - "language to specify syntax guided synthesis problems"

Connected through hyperedge HE-5 (induced by source paper "sygus comp 2016 results and analysis"):
  with members:
    - "using sygus to synthesize reactive motion plans"
    - "language to specify syntax guided synthesis problems"

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)