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: "A foundation of CODD's relational maybe-operations"
  Abstract: Database relations which possibly contain maybe-tuples and null values of type “value at present unknown” are studied. Maybe-tuples and null values are formally interpreted by our notion of  representation , which uses classical notions of predicate logic, elaborates Codd's proposal of maybe-tuples, and adopts Reiter's concept of a closed world. Precise notions of  information content  and  redundancy , associated with our notion of representation, are investigated.  Extensions of the relational algebra  to relations with maybe-tuples and null values are proposed. Our extensions are essentially Codd's, with some modifications. It is proved that these extensions have natural properties which are formally stated as being  adequate  and  restricted .  By the treatment of difference and division, our formal framework can be used even for operations that require “negative information.” Finally, extensions of  update operations  are discussed.

Connected through hyperedge HE-1 (induced by source paper "Logic and databases: a 20 year retrospective"):
  with members:
    - "Managing requirements inconsistency with development goal monitors"

Connected through hyperedge HE-2 (induced by source paper "Relational database: a practical foundation for productivity"):
  with members:
    - "Query by example"
    - "Human Factors Studies of Database Query Languages: A Survey and Assessment"
    - "Performance of graph query languages: comparison of cypher, gremlin and native access in Neo4j"

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