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: "Abstract disjunctive answer set solvers"
  Abstract: A fundamental task in answer set programming is to compute answer sets of logic programs. Answer set solvers are the programs that perform this task. The problem of deciding whether a disjunctive program has an answer set is ΣP2 -complete. The high complexity of reasoning within disjunctive logic programming is responsible for few solvers capable of dealing with such programs, namely DLV, GNT, CMODELS and CLASP. We show that transition systems introduced by Nieuwenhuis, Oliveras, and Tinelli to model and analyze satisfiability solvers can be adapted for disjunctive answer set solvers. In particular, we present transition systems for CMODELS (without backjumping and learning), GNT and DLV (without backjumping). The unifying perspective of transition systems on satisfiability and non-disjunctive answer set solvers proved to be an effective tool for analyzing, comparing, proving correctness of each underlying search algorithm as well as bootstrapping new algorithms. Given this, we believe that this work will bring clarity and inspire new ideas in design of more disjunctive answer set solvers.

Connected through hyperedge HE-1 (induced by source paper "Solving SAT and SAT Modulo Theories: From an abstract Davis--Putnam--Logemann--Loveland procedure to DPLL( T )"):
  with members:
    - "Potassco: The Potsdam Answer Set Solving Collection"
    - "Efficient conflict driven learning in a boolean satisfiability solver"
    - "Lazy explanations for constraint propagators"
    - "Volume Computation for Boolean Combination of Linear Arithmetic Constraints"
    - "There are no CNF problems"
    - "Congruence closure of compressed terms in polynomial time"

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