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: "Integrating Real Time into Spin: A Prototype Implementation"
  Abstract: We present a discrete-time extension of Promela, a high level modelling language for the specification of concurrent systems, and the associated Spin model checker. Our implementation is fully compatible with Spin’s partial order reduction algorithm, which is indeed one of its main strengths. The real time package is for most part orthogonal to the other features of the tool, resulting in a modular extension. We have evaluated it by several experiments, with encouraging results.

Connected through hyperedge HE-1 (induced by source paper "Extending Promela and Spin for Real Time"):
  with members:
    - "An implementation of three algorithms for timing verification based on automata emptiness"

Connected through hyperedge HE-2 (induced by source paper "Model Checking SDL with Spin"):
  with members:
    - "IF: A Validation Environment for Timed Asynchronous Systems"

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