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 "Brooks' Theorem via the Alon-Tarsi Theorem"):
  Abstract: We give a proof of Brooks' Theorem and its choosability extension based on the Alon-Tarsi Theorem; this also shows that Brooks' Theorem remains valid in a more general game coloring setting.

Includes members:
  Member "Flexible color lists in Alon and Tarsi's theorem, and time scheduling with unreliable participants.":
    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: Mathematics