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 "HAMPI: a solver for string constraints"):
  Abstract: Many automatic testing, analysis, and verification techniques for programs can be effectively reduced to a constraint generation phase followed by a constraint-solving phase. This separation of concerns often leads to more effective and maintainable tools. The increasing efficiency of off-the-shelf constraint solvers makes this approach even more compelling. However, there are few effective and sufficiently expressive off-the-shelf solvers for string constraints generated by analysis techniques for string-manipulating programs.   We designed and implemented H ampi , a solver for string constraints over fixed-size string variables. H ampi  constraints express membership in regular languages and fixed-size context-free languages. H ampi  constraints may contain context-free-language definitions, regular language definitions and operations, and the membership predicate. Given a set of constraints, H ampi  outputs a string that satisfies all the constraints, or reports that the constraints are unsatisfiable.   H ampi  is expressive and efficient, and can be successfully applied to testing and analysis of real programs. Our experiments use H ampi  in: static and dynamic analyses for finding SQL injection vulnerabilities in Web applications; automated bug finding in C programs using systematic testing; and compare H ampi  with another string solver. H ampi's  source code, documentation, and the experimental data are available at http://people.csail.mit.edu/akiezun/hampi.

Includes members:
  Member "Sound and precise analysis of web applications for injection vulnerabilities":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "TAJ: effective taint analysis of web applications")
  Member "CUTE: a concolic unit testing engine for C":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "Concolic Execution and Test Case Generation in Prolog")
  Member "Vejovis: suggesting fixes for JavaScript faults":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "RETRACTED ARTICLE: Facilitating debugging of web applications through recording reduction: A family of empirical studies")
  Member "Effective Search-Space Pruning for Solvers of String Equations, Regular Expressions and Length Constraints":
    also connected through other hyperedges:
      (none)

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