(** ** Results about [of_nat] and [of_succ_nat] *)

Lemma succ_of_nat (n:nat) : n<>O -> succ (of_nat n) = of_succ_nat n.
Inductive SqrtSpec : positive*mask -> positive -> Prop :=
| SqrtExact s x : x=s*s -> SqrtSpec (s,IsNul) x
| SqrtApprox s r x : x=s*s+r -> r <= s~0 -> SqrtSpec (s,IsPos r) x.