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: "approximating petri net reachability along context free traces"
  Abstract: We investigate the problem asking whether the intersection of a context-free language (CFL) and a Petri net language (PNL) (with reachability as acceptance condition) is empty. Our contribution to solve this long-standing problem which relates, for instance, to the reachability analysis of recursive programs over unbounded data domain, is to identify a class of CFLs called the finiteindex CFLs for which the problem is decidable. The k-index approximation of a CFL can be obtained by discarding all the words that cannot be derived within a budget k on the number of occurrences of non-terminals. A finite-index CFL is thus a CFL which coincides with its k-index approximation for some k. We decide whether the intersection of a finite-index CFL and a PNL is empty by reducing it to the reachability problem of Petri nets with weak inhibitor arcs, a class of systems with infinitely many states for which reachability is known to be decidable. Conversely, we show that the reachability problem for a Petri net with weak inhibitor arcs reduces to the emptiness problem of a finite-index CFL intersected with a PNL. 1998 ACM Subject Classification D.2.4 Software Engineering/Program Verification

Connected through hyperedge HE-1 (induced by source paper "on functions weakly computable by pushdown petri nets and related systems"):
  with members:
    - "reachability in vector addition systems is primitive recursive in fixed dimension"
    - "the reachability problem for petri nets is not elementary"
    - "reasoning about data repetitions with counter systems"
    - "complexity hierarchies beyond elementary"
    - "on boundedness problems for pushdown vector addition systems"
    - "on the coverability problem for pushdown vector addition systems in one dimension"
    - "the power of priority channel systems"
    - "the reachability problem for vector addition systems with a stack is not elementary"

Connected through hyperedge HE-2 (induced by source paper "coverability is undecidable in one dimensional pushdown vector addition systems with resets"):
  with members:
    - "the emptiness problem for valence automata over graph monoids"
    - "reachability in two dimensional unary vector addition systems with states is nl complete"
    - "reachability in two dimensional vector addition systems with states is pspace complete"
    - "on the coverability problem for pushdown vector addition systems in one dimension"
    - "the reachability problem for vector addition systems with a stack is not elementary"

Connected through hyperedge HE-3 (induced by source paper "the emptiness problem for valence automata over graph monoids"):
  with members:
    - "on the coverability problem for pushdown vector addition systems in one dimension"
    - "computing downward closures for stacked counter automata"
    - "silent transitions in automata with storage"
    - "semilinearity and context freeness of languages accepted by valence automata"

Connected through hyperedge HE-4 (induced by source paper "bounded oscillation pushdown automata"):
  with members:
    - "underapproximation of procedure summaries for integer programs"
    - "parikh s theorem a simple and direct automaton construction"

Connected through hyperedge HE-5 (induced by source paper "decidable models of integer manipulating programs with recursive parallelism technical report"):
  with members:
    - "senescent ground tree rewrite systems"
    - "context bounded analysis for concurrent programs with dynamic creation of threads"

Connected through hyperedge HE-6 (induced by source paper "on the coverability problem for pushdown vector addition systems in one dimension"):
  with members:
    - "reachability in two dimensional vector addition systems with states is pspace complete"
    - "the reachability problem for vector addition systems with a stack is not elementary"
    - "algorithmic verification of asynchronous programs"

Connected through hyperedge HE-7 (induced by source paper "interprocedural reachability for flat integer programs"):
  with members:
    - "underapproximation of procedure summaries for integer programs"
    - "safety problems are np complete for flat integer programs with octagonal loops"
    - "the reachability problem for vector addition systems with a stack is not elementary"
    - "taming past ltl and flat counter systems"
    - "an extension of parikh s theorem beyond idempotence"
    - "the octagon abstract domain"

Connected through hyperedge HE-8 (induced by source paper "model checking vector addition systems with one zero test"):
  with members:
    - "forward analysis for wsts part ii complete wsts"
    - "the general vector addition system reachability problem by presburger inductive invariants"
    - "forward analysis for wsts part i completions"

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.FL(Formal Languages and Automata Theory)