Instructions:
This applet shows that a^{p1} = 1 mod p,
where p is prime and 0< a< p.
Enter a number in box a: and a number in box p:.
Click Doit to see the result of a^{p1}
mod p which is displayed in the unlabeled box.
Click Next to increment a by 1 (mod p) and
repeat the calculation.
Observe:
 What happens when p is nonprime?
 What happens when a > p?
