Nonstandard Graphs
  From any given sequence of finite or infinite graphs, a nonstandard graph is constructed. The procedure is similar to an ultrapower construction of an internal set from a sequence of subsets of the real line, but now the individual entities are the vertices of the graphs instead of real numbers. The transfer principle is then invoked to extend several graph-theoretic results to the nonstandard case. After incidences and adjacencies between nonstandard vertices are defined, several formulas regarding numbers of vertices and edges, and nonstandard versions of Eulerian graphs, Hamiltonian graphs, and a coloring theorem are established for these nonstandard graphs. 
A.H. Zemanian