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: "normal forms for answer sets programming"
  Abstract: Normal forms for logic programs under stable/answer set semantics are introduced. We argue that these forms can simplify the study of program properties, mainly consistency. The first normal form, called the {\em kernel} of the program, is useful for studying existence and number of answer sets. A kernel program is composed of the atoms which are undefined in the Well-founded semantics, which are those that directly affect the existence of answer sets. The body of rules is composed of negative literals only. Thus, the kernel form tends to be significantly more compact than other formulations. Also, it is possible to check consistency of kernel programs in terms of colorings of the Extended Dependency Graph program representation which we previously developed. The second normal form is called {\em 3-kernel.} A 3-kernel program is composed of the atoms which are undefined in the Well-founded semantics. Rules in 3-kernel programs have at most two conditions, and each rule either belongs to a cycle, or defines a connection between cycles. 3-kernel programs may have positive conditions. The 3-kernel normal form is very useful for the static analysis of program consistency, i.e., the syntactic characterization of existence of answer sets. This result can be obtained thanks to a novel graph-like representation of programs, called Cycle Graph which presented in the companion article \cite{Cos04b}.

Connected through hyperedge HE-1 (induced by source paper "about epistemic negation and world views in epistemic logic programs"):
  with members:
    - "splitting epistemic logic programs"
    - "query answering in resource based answer set semantics"
    - "revisiting epistemic specifications"
    - "xsb extending prolog with tabled logic programming"
    - "on the existence of stable models of non stratified logic programs"
    - "transformation based bottom up computation of the well founded model"
    - "extremal problems in logic programming and stable model computation"

Connected through hyperedge HE-2 (induced by source paper "paracoherent answer set semantics meets argumentation frameworks"):
  with members:
    - "better paracoherent answer sets with less resources"
    - "on the computation of paracoherent answer sets"
    - "verifiability of argumentation semantics"
    - "on elementary loops of logic programs"

Connected through hyperedge HE-3 (induced by source paper "graphs and colorings for answer set programming"):
  with members:
    - "the dlv system for knowledge representation and reasoning"
    - "on the problem of computing the well founded semantics"
    - "transformation based bottom up computation of the well founded model"

Connected through hyperedge HE-4 (induced by source paper "on the existence of stable models of non stratified logic programs"):
  with members:
    - "tight logic programs"
    - "diagnostic reasoning with a prolog"
    - "stable models and an alternative logic programming paradigm"

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.AI(Artificial Intelligence)