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: "on methods for the formal specification of fault tolerant systems"
  Abstract: This paper introduces different views for understanding#R##N#problems and faults with the goal of defining a method#R##N#for the formal specification of systems. The idea of Layered#R##N#Fault Tolerant Specification (LFTS) is proposed to make the#R##N#method extensible to fault tolerant systems. The principle is layering the specification in different levels, the first one for the normal behavior and the others for the abnormal. The abnormal behavior is described in terms of an Error Injector (EI), which represents a model of the erroneous interference coming from the environment. This structure has been inspired by the notion of idealized fault tolerant component but the combination of LFTS and EI using Rely/Guarantee reasoning to describe their interaction can be considered as a novel contribution. The#R##N#progress toward this method and this way to organize fault#R##N#tolerant specifications has been made experimenting on case#R##N#studies and an example is presented.

Connected through hyperedge HE-1 (induced by source paper "microservice based iot for smart buildings"):
  with members:
    - "towards microservices and beyond an incoming paradigm shift in distributed computing"
    - "process aware web programming with jolie"
    - "aiocj a choreographic framework for safe adaptive distributed applications"
    - "deriving specifications of dependable systems toward a method"

Connected through hyperedge HE-2 (induced by source paper "model checking of bpmn models for reconfigurable workflows"):
  with members:
    - "on modelling and analysis of dynamic reconfiguration of dependable real time systems"
    - "deriving specifications of dependable systems toward a method"

Connected through hyperedge HE-3 (induced by source paper "lessons from deployment"):
  with members:
    - "deriving specifications of dependable systems toward a method"

Connected through hyperedge HE-4 (induced by source paper "an ltl semantics of business workflows with recovery"):
  with members:
    - "deriving specifications of dependable systems toward a method"

Connected through hyperedge HE-5 (induced by source paper "towards a formalism based toolkit for automotive applications"):
  with members:
    - "deriving specifications of dependable systems toward a method"

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.SE(Software Engineering)