#[local]
Hint Resolve powerRZ_O powerRZ_1 powerRZ_NOR powerRZ_add: real.

Lemma powerRZ_ind (P : Z -> R -> R -> Prop) :
(forall x, P 0 x 1%R) ->
(forall x n, P (Z.of_nat n) x (x ^ n)%R) ->
(forall x n, P ((-(Z.of_nat n))%Z) x (Rinv (x ^ n))) ->
forall x (m : Z), P m x (powerRZ x m)%R.