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: "Class-Based versus Object-Based: A Denotational Comparison"
  Abstract: In object-oriented programming one distinguishes two kinds of languages. Class-based languages are centered around the concept of classes as descriptions of objects. In object-based languages the concept of a class is substituted by constructs for the creation of individual objects. Usually, the object-based languages attract interest because of their "simplicity". This paper contains a thorough denotational analysis which reveals that simplicity is quickly lost if one tackles verification issues. This is due to what is sometimes called "recursion through the store". By providing a denotational semantics for a simple class-based and a simple object-based language it is shown that the denotational semantics of the object-based language needs much more advanced domain theoretic machinery than the class based one. The gap becomes even wider when we define concepts of specification and appropriate verification rules.

Connected through hyperedge HE-1 (induced by source paper "Semantics and logic of object calculi"):
  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: Computer science