#[global]
Instance CR_cv_morph
  : forall {R : ConstructiveReals} (un : nat -> CRcarrier R), CMorphisms.Proper
      (CMorphisms.respectful (CReq R) CRelationClasses.iffT) (CR_cv R un).

Lemma CR_cv_abs_cont : forall {R : ConstructiveReals} (u : nat -> CRcarrier R) (s : CRcarrier R), CR_cv R u s -> CR_cv R (fun n => CRabs R (u n)) (CRabs R s).