In this paper, the theory about 4NF decision in a mixed hypergraph is discussed, and then an algorithm to decide if the relational schema belongs to 4NF is given.

• 摘要本文讨论了混合超图中与4NF判定有关的理论，并在此基础上给出了一个对应的关系模式是否属于4NF的判定算法。