The Seven Bridges of Konigsberg

The river Pregel in East Prussia divides the city into four parts, which are connected with seven bridges as illustrated in Eigure 1.4. The inhabitants of the city were 

FIGURE 1.4 Schematic map of the city of Konigsberg and its seven bridges. 

Definition 1 A Euler path is a path in a graph G that traverses each edge of G exactly once. 

We can now state the Euler theorem, which resolved the problem of the Konigsberg bridges. 

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