The Formalization of Simple Graphs
نویسنده
چکیده
A formalization of simple graphs is given from scratch. There is already an article [10], dealing with the similar subject. It is not used as a starting-point, because [10] formalizes directed non-empty graphs. Given a set of vertices, edge is defined as an (unordered) pair of different two vertices and graph as a pair of a set of vertices and a set of edges. The following concepts are introduced: • simple graph structure, • the set of all simple graphs, • equality relation on graphs. • the notion of degrees of vertices; the number of edges connected to, or the number of adjacent vertices, • the notion of subgraphs, • path, cycle, • complete and bipartite complete graphs,
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تاریخ انتشار 1994