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: "proceedings international workshop on the acl2 theorem prover and its applications"
  Abstract: This volume contains the proceedings of the Eleventh International Workshop on the ACL2 Theorem Prover and its Applications, held on May 30 and 31, 2013, in Laramie, Wyoming, USA. #R##N#ACL2 is an industrial-strength automated reasoning system, the latest in the Boyer-Moore family of theorem provers. The ACL2 workshop is the major technical forum for users of the ACL2 theorem proving system to present research on the prover and its applications. #R##N#This year's workshop received 15 submissions covering a wide range of applications, libraries, prover enhancements, interfaces, and experience reports. 11 papers were selected by the program committee for presentation at the workshop.

Connected through hyperedge HE-1 (induced by source paper "proceedings of the 15th international workshop on the acl2 theorem prover and its applications a toolbox for property checking from simulation using incremental sat extended abstract"):
  with members:
    - "proceedings twelfth international workshop on the acl2 theorem prover and its applications"
    - "verified aig algorithms in acl2"
    - "bit blasting acl2 theorems"
    - "proceedings 10th international workshop on the acl2 theorem prover and its applications"

Connected through hyperedge HE-2 (induced by source paper "a macro for reusing abstract functions and theorems"):
  with members:
    - "how can i do that with acl2 recent enhancements to acl2"

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.LO(Logic in Computer Science)