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: "context unification is in pspace"
  Abstract: Contexts are terms with one `hole', i.e. a place in which we can substitute an argument. In context unification we are given an equation over terms with variables representing contexts and ask about the satisfiability of this equation. Context unification is a natural subvariant of second-order unification, which is undecidable, and a generalization of word equations, which are decidable, at the same time. It is the unique problem between those two whose decidability is uncertain (for already almost two decades). In this paper we show that the context unification is in PSPACE. The result holds under a (usual) assumption that the first-order signature is finite. #R##N#This result is obtained by an extension of the recompression technique, recently developed by the author and used in particular to obtain a new PSPACE algorithm for satisfiability of word equations, to context unification. The recompression is based on performing simple compression rules (replacing pairs of neighbouring function symbols), which are (conceptually) applied on the solution of the context equation and modifying the equation in a way so that such compression steps can be in fact performed directly on the equation, without the knowledge of the actual solution.

Connected through hyperedge HE-1 (induced by source paper "matching patterns with variables"):
  with members:
    - "graph and string parameters connections between pathwidth cutwidth and the locality number"
    - "quadratic word equations with length constraints counter systems and presburger arithmetic with divisibility"
    - "the hardness of solving simple word equations"
    - "the runs theorem"
    - "decidability complexity and expressiveness of first order logic over the subword ordering"
    - "detecting one variable patterns"
    - "solutions of word equations over partially commutative structures"
    - "a parameterized study of maximum generalized pattern matching problems"

Connected through hyperedge HE-2 (induced by source paper "grammar based compression of unranked trees"):
  with members:
    - "balancing straight line programs"
    - "slowing down top trees for better worst case bounds"
    - "schemas for unordered xml on a dime"
    - "compressed tree canonization"
    - "tree compression with top trees revisited"
    - "faster fully compressed pattern matching by recompression"

Connected through hyperedge HE-3 (induced by source paper "inter procedural two variable herbrand equalities"):
  with members:
    - "linear compressed pattern matching for polynomial rewriting extended abstract"

Connected through hyperedge HE-4 (induced by source paper "one variable word equations in linear time"):
  with members:
    - "the complexity of compressed membership problems for finite automata"
    - "approximation of grammar based compression via recompression"
    - "approximation of smallest linear tree grammar"
    - "recompression a simple and powerful technique for word equations"
    - "faster fully compressed pattern matching by recompression"

Connected through hyperedge HE-5 (induced by source paper "recompression a simple and powerful technique for word equations"):
  with members:
    - "the complexity of compressed membership problems for finite automata"
    - "a really simple approximation of smallest grammar"
    - "finding all solutions of equations in free groups and monoids with involution"
    - "approximation of grammar based compression via recompression"
    - "approximation of smallest linear tree grammar"
    - "one variable word equations in linear time"
    - "faster fully compressed pattern matching by recompression"

Connected through hyperedge HE-6 (induced by source paper "faster fully compressed pattern matching by recompression"):
  with members:
    - "the complexity of compressed membership problems for finite automata"
    - "approximation of grammar based compression via recompression"
    - "approximation of smallest linear tree grammar"
    - "one variable word equations in linear time"
    - "recompression a simple and powerful technique for word equations"
    - "tying up the loose ends in fully lzw compressed pattern matching"
    - "pattern matching in lempel ziv compressed strings fast simple and deterministic"
    - "identifying hierarchical structure in sequences a linear time algorithm"

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)