human: Given a node-centered hypergraph: <hypergraph>, where nodes represent authors and hyperedges represent groups of authors who co-authored the same paper.

Details of the hypergraph:
Center node: "Orthopairs: A Simple and Widely UsedWay to Model Uncertainty"
  Abstract: The term orthopair is introduced to group under a unique definition different ways used to denote the same concept. Some orthopair models dealing with uncertainty are analyzed both from a mathematical and semantical point of view, outlining similarities and differences among them. Finally, lattice operations on orthopairs are studied and a survey on algebraic structures is provided.

Connected through hyperedge HE-1 (induced by source paper "Truth-Functionality, Rough Sets and Three-Valued Logics"):
  with members:
    (none)

Connected through hyperedge HE-2 (induced by source paper "Generalized Orthopair Fuzzy Sets"):
  with members:
    - "Some q-Rung Dual Hesitant Fuzzy Heronian Mean Operators with Their Application to Multiple Attribute Group Decision-Making"

Question: Please tell me which research area the center author belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Mathematics