Isomorphism¶

Returns True if the graphs G1 and G2 are isomorphic and False otherwise. 

Returns False if graphs are definitely not isomorphic. 

Returns False if graphs are definitely not isomorphic. 

Returns False if graphs are definitely not isomorphic. 
Tree Isomorphism¶
An algorithm for finding if two undirected trees are isomorphic, and if so returns an isomorphism between the two sets of nodes.
This algorithm uses a routine to tell if two rooted trees (trees with a specified root node) are isomorphic, which may be independently useful.
This implements an algorithm from: The Design and Analysis of Computer Algorithms by Aho, Hopcroft, and Ullman AddisonWesley Publishing 1974 Example 3.2 pp. 8486.
A more understandable version of this algorithm is described in: Homework Assignment 5 McGill University SOCS 308250B, Winter 2002 by Matthew Suderman http://crypto.cs.mcgill.ca/~crepeau/CS250/2004/HW5+.pdf

Given two rooted trees 

Given two undirected (or free) trees 