Network Notes Ms Allan 2012 AS91260 (2.5) Designed to teach from, Not as complete notes.
ABC and D are Nodes or Vertices
BC is an arc, edge or path
There are two arc, edge or paths between A and B There are two arc, edge or paths between A and B. Lets call them AB1 and AB2.
A has two arcs: it is an even Node.
B has 6 arcs, it is an even Node.
All Nodes are even => Traversable.
Node B has 7 arcs: it is an odd node Node B has 7 arcs: it is an odd node. Node C has 5 arcs: it is an even node.
This network has Exactly 2 odd nodes: It is traversable starting at one odd node and ending at the other odd node.
More than 2 odd nodes? Not traversable!