#[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_dist_cont : forall {R : ConstructiveReals} (u : nat -> CRcarrier R) (a s : CRcarrier R), CR_cv R u s -> CR_cv R (fun n => CRabs R (a - u n)) (CRabs R (a - s)).