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 practical soft type system for scheme"
  Abstract: A  soft type system  infers types for the procedures and data structures of dynamically typed programs. Like conventional static types, soft types express program invariants and thereby provide valuable information for program optimization and debugging. A soft type  checker  uses the types inferred by a soft type system to eliminate run-time checks that are provably unnecessary; any remaining run-time checks are flagged as potential program errors.  Soft Scheme  is a practical soft type checker for R4RS Scheme. Its underlying type system generalizes conventional Hindley-Milner type inference by incorporating recursive types and a limited form of union type. Soft Scheme accommodates all of R4RS Scheme including uncurried procedures of  fixed and variable arity, assignment, and continuations.

Connected through hyperedge HE-1 (induced by source paper "Dynamic typing in a statically typed language"):
  with members:
    - "Types and persistence in database programming languages"
    - "Compiling polymorphism using intensional type analysis"
    - "JavaScript as an embedded DSL"

Connected through hyperedge HE-2 (induced by source paper "Securing web application code by static analysis and runtime protection"):
  with members:
    - "Language-based information-flow security"
    - "Sound and precise analysis of web applications for injection vulnerabilities"

Connected through hyperedge HE-3 (induced by source paper "Detecting Software Defects in Telecom Applications Through Lightweight Static Analysis: A War Story"):
  with members:
    - "TypEr : a type annotator of Erlang code"

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