Hm..the controlLogix has a fuzzy logic add-on. I've never used it, so I can't be of much help. However, I did write some fuzzy logic stuff in Java and I can imagine that doing it in ladder would be a big PITA
What exactly do you need the program to do? Are you sure you need fussy logic? Please explain to use what you want to have your program do so people can help you with a better understanding of what you want to accomplish. Sincerely: Maintenance Man.