(*********************************************************)
(** ** Square function                                   *)
(*********************************************************)

Definition Rsqr r : R := r * r.Notation "r ²" := (Rsqr r) (at level 1, format "r ²") : R_scope.

Lemma Rplus_nneg_ge : forall r1 r2, r2 >= 0 -> r1 + r2 >= r1.