Hi!
Using table-filling method, how do I prove that states A and B are distinguishable? A,C and B,C initially marked pairs are obviously allright, but then when I look at A,B , there is no symbol s in the alphabet {1,2,3} that I can use to analyze a pair of "simultaneous" transitions sigma(A, s) and sigma(B, s), where sigma is a transition function.
Is this method unfit for the task? If that is the case, what would you recommend to use instead (I'm writing a program that takes DFA on ASCII alphabet and minimizes it)?

"If two states s1 and s2 have transitions on the same symbol c to states t1 and t2 that we have already proven to be different, then s1 and s2 are different. This also applies if only one of s1 or s2 have a defined transition on c."
Looks like this situation automatically means distinguished states.
– Boris-Barboris Sep 07 '17 at 22:20