intros e z; case z; simpl in |- *; auto with real.
Qed.
Hint Resolve powerRZ_O powerRZ_1 powerRZ_NOR: real.

Theorem powerRZ_add :
forall (e : R) (n m : BinInt.Z),
e <> 0%R -> powerRZ e (n + m) = (powerRZ e n * powerRZ e m)%R.