4. For any prime p, m (p) = -1.
Proof:
By definition, ( ) ( )r m n = -1 for ... , 1 2 r n = p p p where i p is any distinct prime.
Since p is a distinct prime, then
( ) ( 1) 1. 1 m p = - = - ◄
The above first three statements can be further lumped into one