Hey, 

I know what is spraguey grundy theorem, but I want to know about generalized spraguey grundy (GSG) theorem ( which is used for games with cycles ). Apparently there seems to be very less resources available on net which mentions GSG Theorem. Plus it would be really helpful if anyone can provide me any link containing code (preferably in python) to find Spraguey Grundy Number of a position. 


Thank you