摘要
The definition for acyclic hypergraphs follows from that for acyclic database schemes. Based on topological structure of Hasse diagram of semilattices, Lee number was proved to be an invariant for hypergraphs, and a necessary and sufficient condition for a hypergraph to be acyclic was given in this paper. Some properties of acyclic hypergraphs were discussed. Some relations for Lee number with several quantities in discrete mathematics were also obtained. We simply discussed some applications of the results in this paper.
The definition for acyclic hypergraphs follows from that for acyclic database schemes. Based on topological structure of Hasse diagram of semilattices, Lee number was proved to be an invariant for hypergraphs, and a necessary and sufficient condition for a hypergraph to be acyclic was given in this paper. Some properties of acyclic hypergraphs were discussed. Some relations for Lee number with several quantities in discrete mathematics were also obtained. We simply discussed some applications of the results in this paper.
