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: "Theory Morphisms in Church’s Type Theory with Quotation and Evaluation"
  Abstract: \({\textsc {ctt}}_\mathrm{qe}\) is a version of Church’s type theory with global quotation and evaluation operators that is engineered to reason about the interplay of syntax and semantics and to formalize syntax-based mathematical algorithms. \({\textsc {ctt}}_\mathrm{uqe}\) is a variant of \({\textsc {ctt}}_\mathrm{qe}\) that admits undefined expressions, partial functions, and multiple base types of individuals. It is better suited than \({\textsc {ctt}}_\mathrm{qe}\) as a logic for building networks of theories connected by theory morphisms. This paper presents the syntax and semantics of \({\textsc {ctt}}_\mathrm{uqe}\), defines a notion of a theory morphism from one \({\textsc {ctt}}_\mathrm{uqe}\) theory to another, and gives two simple examples involving monoids that illustrate the use of theory morphisms in \({\textsc {ctt}}_\mathrm{uqe}\).

Connected through hyperedge HE-1 (induced by source paper "Incorporating quotation and evaluation into Church's type theory"):
  with members:
    (none)

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