Add Parametric Morphism {R : ConstructiveReals} : CRmin
    with signature (CReq R) ==> (CReq R) ==> (CReq R)
      as CRmin_morph.#[global]
Instance CRmin_morphT
  : forall {R : ConstructiveReals},
    CMorphisms.Proper
      (CMorphisms.respectful (CReq R) (CMorphisms.respectful (CReq R) (CReq R))) (@CRmin R).

Lemma CRmin_plus : forall {R : ConstructiveReals} (x y z : CRcarrier R), x + CRmin y z == CRmin (x + y) (x + z).