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: "an implementation of cad in maple utilising problem formulation equational constraints and truth table invariance"
  Abstract: Cylindrical algebraic decomposition (CAD) is an important tool for the investigation of semi-algebraic sets, with applications within algebraic geometry and beyond. We recently reported on a new implementation of CAD in Maple which implemented the original algorithm of Collins and the subsequent improvement to projection by McCallum. Our implementation was in contrast to Maple’s in-built CAD command, based on a quite separate theory. Although initially developed as an investigative tool to compare the algorithms, we found and reported that our code offered functionality not currently available in any other existing implementations. One particularly important piece of functionality is the ability to produce order-invariant CADs. This has allowed us to extend the implementation to produce CADs invariant with respect to either equational constraints (ECCADs) or the truth-tables of sequences of formulae (TTICADs). This new functionality is contained in the second release of our code, along with commands to consider problem formulation which can be a major factor in the tractability of a CAD. In the report we describe the new functionality and some theoretical discoveries it prompted. We describe how the CADs produced using equational constraints are able to take advantage of not just improved projection but also improvements in the lifting phase. We also present an extension to the original TTICAD algorithm which increases both the applicability of TTICAD and its relative benefit over other algorithms. The code and an introductory Maple worksheet / pdf demonstrating the full functionality of the package should accompany this report.

Connected through hyperedge HE-1 (induced by source paper "truth table invariant cylindrical algebraic decomposition"):
  with members:
    - "improving the use of equational constraints in cylindrical algebraic decomposition"
    - "truth table invariant cylindrical algebraic decomposition by regular chains"
    - "applying machine learning to the problem of choosing a heuristic to select the variable ordering for cylindrical algebraic decomposition"
    - "choosing a variable ordering for truth table invariant cylindrical algebraic decomposition by incremental triangular decomposition"
    - "cylindrical algebraic decomposition using local projections"
    - "using the distribution of cells by dimension in a cylindrical algebraic decomposition"
    - "problem formulation for truth table invariant cylindrical algebraic decomposition by incremental triangular decomposition"
    - "using the regular chains library to build cylindrical algebraic decompositions by projecting and lifting"

Connected through hyperedge HE-2 (induced by source paper "an implementation of sub cad in maple"):
  with members:
    - "truth table invariant cylindrical algebraic decomposition"
    - "truth table invariant cylindrical algebraic decomposition by regular chains"
    - "using the distribution of cells by dimension in a cylindrical algebraic decomposition"
    - "problem formulation for truth table invariant cylindrical algebraic decomposition by incremental triangular decomposition"
    - "using the regular chains library to build cylindrical algebraic decompositions by projecting and lifting"
    - "cylindrical algebraic sub decompositions"
    - "an implementation of cad in maple utilising mccallum projection"
    - "cylindrical algebraic decompositions for boolean combinations"

Connected through hyperedge HE-3 (induced by source paper "using the regular chains library to build cylindrical algebraic decompositions by projecting and lifting"):
  with members:
    - "truth table invariant cylindrical algebraic decomposition"
    - "truth table invariant cylindrical algebraic decomposition by regular chains"
    - "problem formulation for truth table invariant cylindrical algebraic decomposition by incremental triangular decomposition"
    - "cylindrical algebraic sub decompositions"
    - "understanding branch cuts of expressions"
    - "an implementation of cad in maple utilising mccallum projection"
    - "cylindrical algebraic decompositions for boolean combinations"
    - "optimising problem formulation for cylindrical algebraic decomposition"

Connected through hyperedge HE-4 (induced by source paper "truth table invariant cylindrical algebraic decomposition by regular chains"):
  with members:
    - "truth table invariant cylindrical algebraic decomposition"
    - "choosing a variable ordering for truth table invariant cylindrical algebraic decomposition by incremental triangular decomposition"
    - "problem formulation for truth table invariant cylindrical algebraic decomposition by incremental triangular decomposition"
    - "using the regular chains library to build cylindrical algebraic decompositions by projecting and lifting"
    - "cylindrical algebraic sub decompositions"
    - "understanding branch cuts of expressions"
    - "cylindrical algebraic decompositions for boolean combinations"
    - "optimising problem formulation for cylindrical algebraic decomposition"

Connected through hyperedge HE-5 (induced by source paper "cylindrical algebraic sub decompositions"):
  with members:
    - "truth table invariant cylindrical algebraic decomposition"
    - "understanding branch cuts of expressions"
    - "applications of continuous amortization to bisection based root isolation"
    - "an implementation of cad in maple utilising mccallum projection"
    - "cylindrical algebraic decompositions for boolean combinations"
    - "optimising problem formulation for cylindrical algebraic decomposition"
    - "a piano movers problem reformulated"
    - "an incremental algorithm for computing cylindrical algebraic decompositions"

Connected through hyperedge HE-6 (induced by source paper "problem formulation for truth table invariant cylindrical algebraic decomposition by incremental triangular decomposition"):
  with members:
    - "truth table invariant cylindrical algebraic decomposition"
    - "truth table invariant cylindrical algebraic decomposition by regular chains"
    - "understanding branch cuts of expressions"
    - "cylindrical algebraic decompositions for boolean combinations"
    - "optimising problem formulation for cylindrical algebraic decomposition"
    - "an incremental algorithm for computing cylindrical algebraic decompositions"
    - "program verification in the presence of complex numbers functions with branch cuts etc"
    - "computing cylindrical algebraic decomposition via triangular decomposition"

Connected through hyperedge HE-7 (induced by source paper "applying machine learning to the problem of choosing a heuristic to select the variable ordering for cylindrical algebraic decomposition"):
  with members:
    - "cylindrical algebraic decompositions for boolean combinations"
    - "optimising problem formulation for cylindrical algebraic decomposition"
    - "a piano movers problem reformulated"
    - "program verification in the presence of complex numbers functions with branch cuts etc"
    - "computing cylindrical algebraic decomposition via triangular decomposition"
    - "machine learning in automated text categorization"

Connected through hyperedge HE-8 (induced by source paper "a piano movers problem reformulated"):
  with members:
    - "cylindrical algebraic sub decompositions"
    - "an implementation of cad in maple utilising mccallum projection"
    - "cylindrical algebraic decompositions for boolean combinations"
    - "optimising problem formulation for cylindrical algebraic decomposition"
    - "program verification in the presence of complex numbers functions with branch cuts etc"
    - "computing cylindrical algebraic decomposition via triangular decomposition"

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.SC(Symbolic Computation)