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 hypergraph based approach for the 4 constraint satisfaction problem tractability"):
  Abstract: Constraint Satisfaction Problem (CSP) is a framework for modeling and solving a variety of real-world problems. Once the problem is expressed as a finite set of constraints, the goal is to find the variables' values satisfying them. Even though the problem is in general NP-complete, there are some approximation and practical techniques to tackle its intractability. One of the most widely used techniques is the Constraint Propagation. It consists in explicitly excluding values or combination of values for some variables whenever they make a given subset of constraints unsatisfied. In this paper, we deal with a CSP subclass which we call 4-CSP and whose constraint network infers relations of the form: $\{ x \sim \alpha, x-y \sim \beta , (x-y) - (z-t) \sim \lambda \}$, where $x, y, z$ and $t$ are real variables, $\alpha , \beta$ and $ \lambda $ are real constants and $ \sim \in \{\leq , \geq \} $. The paper provides the first graph-based proofs of the 4-CSP tractability and elaborates algorithms for 4-CSP resolution based on the positive linear dependence theory, the hypergraph closure and the constraint propagation technique. Time and space complexities of the resolution algorithms are proved to be polynomial.

Includes members:
  Member "language emptiness of continuous time parametric timed automata":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "consistency in parametric interval probabilistic timed automata")
  Member "schaefer s theorem for graphs":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "when symmetries are not enough a hierarchy of hard constraint satisfaction problems")
  Member "a new numerical abstract domain based on difference bound matrices":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "deterministic parallel fixpoint computation")
  Member "the octagon abstract domain":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "reludiff differential verification of deep neural networks")
  Member "a static analyzer for large safety critical software":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "automatically proving microkernels free from privilege escalation from their executable")
  Member "the essence of constraint propagation":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "spacetime programming a synchronous language for composable search strategies")

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.DM(Discrete Mathematics)