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: "formal verification of obstacle avoidance and navigation of ground robots"
  Abstract: This article answers fundamental safety questions for ground robot navigation: under which circumstances does which control decision make a ground robot safely avoid obstacles? Unsurprisingly, the answer depends on the exact formulation of the safety objective, as well as the physical capabilities and limitations of the robot and the obstacles. Because uncertainties about the exact future behavior of a robot’s environment make this a challenging problem, we formally verify corresponding controllers and provide rigorous safety proofs justifying why the robots can never collide with the obstacle in the respective physical model. To account for ground robots in which different physical phenomena are important, we analyze a series of increasingly strong properties of controllers for increasingly rich dynamics and identify the impact that the additional model parameters have on the required safety margins. We analyze and formally verify: (i) static safety, which ensures that no collisions can happen with stati...

Connected through hyperedge HE-1 (induced by source paper "overview of logical foundations of cyber physical systems"):
  with members:
    - "uniform substitution in one fell swoop"
    - "verifiably safe off model reinforcement learning"
    - "differential equation axiomatization the impressive power of differential ghosts"
    - "the keymaera x proof ide concepts on usability in hybrid systems theorem proving"

Connected through hyperedge HE-2 (induced by source paper "a formal safety net for waypoint following in ground robots"):
  with members:
    - "verified runtime validation for partially observable hybrid systems"
    - "airsim high fidelity visual and physical simulation for autonomous vehicles"
    - "formal verification of station keeping maneuvers for a planar autonomous hybrid system"

Connected through hyperedge HE-3 (induced by source paper "blackbox end to end verification of ground robot safety and liveness"):
  with members:
    - "airsim high fidelity visual and physical simulation for autonomous vehicles"

Connected through hyperedge HE-4 (induced by source paper "formal specification and verification of autonomous robotic systems a survey"):
  with members:
    - "modular verification of vehicle platooning with respect to decisions space and time"
    - "automating verification of state machines with reactive designs and isabelle utp"
    - "robotics and integrated formal methods necessity meets opportunity"
    - "developing bug free machine learning systems with formal mathematics"
    - "a rational agent controlling an autonomous vehicle implementation and formal verification"
    - "a stochastically verifiable autonomous control architecture with reasoning"
    - "towards the verification of safety critical autonomous systems in dynamic environments"
    - "formal specification and analysis of autonomous systems under partial compliance"

Connected through hyperedge HE-5 (induced by source paper "verified runtime validation for partially observable hybrid systems"):
  with members:
    - "differential equation axiomatization the impressive power of differential ghosts"
    - "soter programming safe robotics system using runtime assurance"
    - "a complete uniform substitution calculus for differential dynamic logic"
    - "fastrack a modular framework for fast and guaranteed safe motion planning"
    - "robust online monitoring of signal temporal logic"
    - "on line monitoring for temporal logic robustness"
    - "counter strategy guided refinement of gr 1 temporal logic specifications"

Connected through hyperedge HE-6 (induced by source paper "reactive integrated mission and motion planning"):
  with members:
    - "bounded reachability for temporal logic over constraint systems"

Connected through hyperedge HE-7 (induced by source paper "a corroborative approach to verification and validation of human robot teams"):
  with members:
    - "testing verification and improvements of timeliness in ros processes"
    - "a model for safety case confidence assessment"
    - "coverage driven verification an approach to verify code for robots that directly interact with humans"
    - "systematic and realistic testing in simulation of control code for robots in collaborative human robot interactions"
    - "towards the safety of human in the loop robotics challenges and opportunities for safety assurance of robotic co workers"

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.SY(Systems and Control)