#[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_nonneg : forall {R : ConstructiveReals} (An:nat -> CRcarrier R) (l:CRcarrier R), CR_cv R An l -> (forall n:nat, 0 <= An n) -> 0 <= l.