Definition CReal_plus (x y : CReal) : CReal :=
{|
seq := CReal_plus_seq x y;
scale := CReal_plus_scale x y;
cauchy := CReal_plus_cauchy x y;
bound := CReal_plus_bound x y
|}.
Infix "+" := CReal_plus : CReal_scope.
Definition CReal_opp_seq (x : CReal) :=
(fun n : Z => - seq x n).
Definition CReal_opp_scale (x : CReal) : Z :=
x.(scale).

Lemma CReal_opp_bound : forall (x : CReal),
QBound (CReal_opp_seq x) (CReal_opp_scale x).