Abstract:

We defined the so-called B graph in research on concurrent program complexity metrics as one the models of rendezvous relations in Ada programs. In this paper, we investigate a special case of  B graph ----- BB graph, and call it chain-like graph. A BB graph of order n is the oriented tree of order n and height n-1by adding some edges with the constraint that both of the in-degree and out-degree for every node are two at most. The paper gives some enumerating characteristics of BB Graph, and points out the closed relationship with the Stirling numbers of second kind.

Key words: Concurrent program complexity metrics, Chain-like graph, Stirling numbers of second kind