[Jtsummers]

> a^n % b = a % b.

That is not generally true. A quick counterexample:

  a = 2, n = 3, b = 5
  2^3 % 5 = 8 % 5 = 3
  2 % 5 = 2
  3 != 2

[anthk]

I was to type something like

       (a ^ n) % n = a % n

[anthk]

I missed something from Groff, sorry.