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: "understanding and formalizing accountability for cyber physical systems"
  Abstract: Accountability is the property of a system that enables the uncovering of causes for events and helps understand who or what is responsible for these events. Definitions and interpretations of accountability differ; however, they are typically expressed in natural language that obscures design decisions and the impact on the overall system. This paper presents a formal model to express the accountability properties of cyber-physical systems. To illustrate the usefulness of our approach, we demonstrate how three different interpretations of accountability can be expressed using the proposed model and describe the implementation implications through a case study. This formal model can be used to highlight context specific-elements of accountability mechanisms, define their capabilities, and express different notions of accountability. In addition, it makes design decisions explicit and facilitates discussion, analysis and comparison of different approaches.

Connected through hyperedge HE-1 (induced by source paper "efficiently checking actual causality with sat solving"):
  with members:
    - "theoretical impediments to machine learning with seven sparks from the causal revolution"
    - "towards formal definitions of blameworthiness intention and moral responsibility"
    - "from causes for database queries to repairs and model based diagnosis and back"
    - "a modification of the halpern pearl definition of causality"
    - "the computational complexity of structure based causality"
    - "the complexity of causality and responsibility for query answers and non answers"
    - "what causes a system to satisfy a specification"
    - "responsibility and blame a structural model approach"

Connected through hyperedge HE-2 (induced by source paper "extending causal models from machines into humans"):
  with members:
    - "a modification of the halpern pearl definition of causality"
    - "dag based attack and defense modeling don t miss the forest for the attack trees"
    - "causes and explanations a structural model approach part ii explanations"

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)