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: "modular fully abstract compilation by approximate back translation"
  Abstract: A compiler is fully-abstract if the compilation from source language programs#N#to target language programs reflects and preserves behavioural equivalence.#N#Such compilers have important security benefits, as they limit the power of an#N#attacker interacting with the program in the target language to that of an#N#attacker interacting with the program in the source language. Proving compiler#N#full-abstraction is, however, rather complicated. A common proof technique is#N#based on the back-translation of target-level program contexts to#N#behaviourally-equivalent source-level contexts. However, constructing such a#N#back- translation is problematic when the source language is not strong enough#N#to embed an encoding of the target language. For instance, when compiling from#N#STLC to ULC, the lack of recursive types in the former prevents such a#N#back-translation.#N#  We propose a general and elegant solution for this problem. The key insight#N#is that it suffices to construct an approximate back-translation. The#N#approximation is only accurate up to a certain number of steps and conservative#N#beyond that, in the sense that the context generated by the back-translation#N#may diverge when the original would not, but not vice versa. Based on this#N#insight, we describe a general technique for proving compiler full-abstraction#N#and demonstrate it on a compiler from STLC to ULC. The proof uses asymmetric#N#cross-language logical relations and makes innovative use of step-indexing to#N#express the relation between a context and its approximate back-translation.#N#The proof extends easily to common compiler patterns such as modular#N#compilation and it, to the best of our knowledge, it is the first compiler full#N#abstraction proof to have been fully mechanised in Coq. We believe this proof#N#technique can scale to challenging settings and enable simpler, more scalable#N#proofs of compiler full-abstraction.

Connected through hyperedge HE-1 (induced by source paper "when good components go bad formally secure compilation despite dynamic compromise"):
  with members:
    - "journey beyond full abstraction exploring robust property preservation for secure compilation"
    - "robust hyperproperty preservation for secure compilation extended abstract"
    - "effectivesan type and memory error detection using dynamically typed c c"
    - "the meaning of memory safety"
    - "beyond good and evil formalizing the security guarantees of compartmentalizing compilation"
    - "towards a fully abstract compiler using micro policies secure compilation for mutually distrustful components"

Connected through hyperedge HE-2 (induced by source paper "robustly safe compilation or efficient provably secure compilation"):
  with members:
    - "trace relating compiler correctness and secure compilation"
    - "journey beyond full abstraction exploring robust property preservation for secure compilation"
    - "robust hyperproperty preservation for secure compilation extended abstract"
    - "beyond good and evil formalizing the security guarantees of compartmentalizing compilation"
    - "a formally verified compiler back end"

Connected through hyperedge HE-3 (induced by source paper "beyond good and evil formalizing the security guarantees of compartmentalizing compilation"):
  with members:
    - "towards a fully abstract compiler using micro policies secure compilation for mutually distrustful components"
    - "a formally verified compiler back end"

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.PL(Programming Languages)