Definition Fabs (x : float) := Float (Zabs (Fnum x)) (Fexp x).

(* Specifications: *)
Theorem Fabs_correct1 : forall x : float, (0 <= FtoR radix x)%R -> Fabs x = x :>R.
Theorem Fabs_correct2 : forall x : float, (FtoR radix x <= 0)%R -> Fabs x = (- x)%R :>R.
Theorem Fabs_correct : forall x : float, Fabs x = Rabs x :>R.
Theorem RleFexpFabs : forall p : float, p <> 0%R :>R -> (Float 1%nat (Fexp p) <= Fabs p)%R.
Theorem Fabs_Fzero : forall x : float, ~ is_Fzero x -> ~ is_Fzero (Fabs x).
Theorem Fdigit_abs : forall x : float, Fdigit radix (Fabs x) = Fdigit radix x.