Grafo de 6 nodos:

Grafo en JMEScriptGUI con visor de grafos v0.1:

{a,e,f} estable:

gr_estable(gr_nuevo([[0,1,1,0,0,0],[1,0,0,1,1,0],[1,0,0,1,0,1],[0,1,1,0,1,1],[0,1,0,1,0,0],[0,0,1,1,0,0]],['a','b','c','d','e','f']),['a','e','f'])

Booleano: verdadero

No es estable {b,c,d}:

gr_estable(gr_nuevo([[0,1,1,0,0,0],[1,0,0,1,1,0],[1,0,0,1,0,1],[0,1,1,0,1,1],[0,1,0,1,0,0],[0,0,1,1,0,0]],['a','b','c','d','e','f']),[1,2,3])

Booleano: falso