human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge groups authors who co-authored the same paper.

Details of the hypergraph:
Center hyperedge (induced by source paper "Schema-based Query Optimization for XQuery Queries."):
  Abstract: XQuery is widely used for querying XML documents. Within this paper, we examine optimization rules for XQuery queries that exploit type information of the input XML document given in XML Schema. These optimization rules are applicable for all XQuery expressions and are very useful e.g. in the scenario of XQuery queries on XQuery views. The basic idea is to transform the XML Schema definition into a graph, which is extended to a graph representing the XQuery expression. The latter graph is used to delete subexpressions of the XQuery expression that are not used to retrieve the final result of the given XQuery expression. We further include experimental results that demonstrate the improvement of our optimization.

Includes members:
  Member "Algebraic Transformation and Optimization for XQuery":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "An Algebra for XML Query")
  Member "XPath Query Simplification with regard to the Elimination of Intersect and Except Operators":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "FILTERING UNSATISFIABLE XPATH QUERIES")

Question: Please tell me which research area the co-authored paper (i.e., the source paper of the center hyperedge) belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Computer science