an-1 == 1 mod n (Fermat's Little Theorem)
bn-1 == 1 mod n
an-1 = (a)an-2 == 1 mod n
bn-1 = (b)bn-2 == 1 mod n
(a)an-2 == (b)bn-2 mod n
If a =/= b mod n
Is it true that
an-2 =/= bn-2 mod n ?