human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "a higher order abstract syntax approach to the verified compilation of functional programs"):
  Abstract: University of Minnesota Ph.D. dissertation.December  2016. Major: Computer Science. Advisor: Gopalan Nadathur. 1 computer file (PDF);  xii, 246 pages.

Includes members:
  Member "a case study on logical relations using contextual types":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "a higher order abstract syntax approach to verified transformations on functional programs")
  Member "the next 700 challenge problems for reasoning with higher order abstract syntax representations part 1 a common infrastructure for benchmarks":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "an open challenge problem repository for systems supporting binders")
  Member "a framework for specifying prototyping and reasoning about computational systems":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "functional programming with λ tree syntax")
  Member "a two level logic approach to reasoning about computations":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "schematic polymorphism in the abella proof assistant")
  Member "the abella interactive theorem prover system description":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "rapid prototyping formal systems in mmt 5 case studies")
  Member "reasoning with higher order abstract syntax in a logical framework":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "formalization of metatheory of the quipper quantum programming language in a linear logic")

Question: Please tell me which class the source paper 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.PL(Programming Languages)