intros x y H' H'0; Contradict H'.
apply is_Fzero_rep2; auto.
rewrite H'0.
apply is_Fzero_rep1; auto.
Qed.
(* Some inegalities that will be helpful *)

Theorem Rlt_monotony_exp :
forall (x y : R) (z : Z),
(x < y)%R -> (x * powerRZ radix z < y * powerRZ radix z)%R.