from graph import Graph

S = Graph('s')
P = Graph('p')       # a graph of spam
A = Graph('a')       # make node objects
M = Graph('m')
    
S.arcs = [P, M]      # S leads to P and M
P.arcs = [S, M, A]   # arcs: embedded objects
A.arcs = [M]
print S.search(M)    # find all paths from S to M