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: "understanding branch cuts of expressions"
  Abstract: We assume some standard choices for the branch cuts of a group of functions and consider the problem of then calculating the branch cuts of expressions involving those functions. Typical examples include the addition formulae for inverse trigonometric functions. Understanding these cuts is essential for working with the single-valued counterparts, the common approach to encoding multi-valued functions in computer algebra systems. While the defining choices are usually simple (typically portions of either the real or imaginary axes) the cuts induced by the expression may be surprisingly complicated. We have made explicit and implemented techniques for calculating the cuts in the computer algebra programme Maple. We discuss the issues raised, classifying the different cuts produced. The techniques have been gathered in the BranchCuts package, along with tools for visualising the cuts. The package is included in Maple 17 as part of the FunctionAdvisor tool.

Connected through hyperedge HE-1 (induced by source paper "using machine learning to improve cylindrical algebraic decomposition"):
  with members:
    - "machine learning for mathematical software"
    - "symbolic versus numerical computation and visualization of parameter regions for multistationarity of biological networks"
    - "a case study on the parametric occurrence of multiple steady states"
    - "need polynomial systems be doubly exponential"
    - "using machine learning to decide when to precondition cylindrical algebraic decomposition with groebner bases"
    - "truth table invariant cylindrical algebraic decomposition"
    - "the complexity of cylindrical algebraic decomposition with respect to polynomial degree"
    - "improving the use of equational constraints in cylindrical algebraic decomposition"

Connected through hyperedge HE-2 (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-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"
    - "an implementation of cad in maple utilising mccallum projection"
    - "an implementation of cad in maple utilising problem formulation equational constraints and truth table invariance"
    - "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"
    - "an implementation of cad in maple utilising problem formulation equational constraints and truth table invariance"
    - "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"
    - "applications of continuous amortization to bisection based root isolation"
    - "an implementation of cad in maple utilising mccallum projection"
    - "an implementation of cad in maple utilising problem formulation equational constraints and truth table invariance"
    - "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 "choosing a variable ordering 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"
    - "applying machine learning to the problem of choosing a heuristic to select the variable ordering for cylindrical algebraic decomposition"
    - "problem formulation for truth table invariant cylindrical algebraic decomposition by incremental triangular decomposition"
    - "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-7 (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"
    - "an implementation of cad in maple utilising problem formulation equational constraints and truth table invariance"
    - "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-8 (induced by source paper "branch cuts in maple 17"):
  with members:
    - "cylindrical algebraic decompositions for boolean combinations"
    - "program verification in the presence of complex numbers functions with branch cuts etc"

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.MS(Mathematical Software)