(** Properties of constructive absolute value (defined in
    ConstructiveReals.CRabs).
    Definition of minimum, maximum and their properties.

    WARNING: this file is experimental and likely to change in future releases.
*)

#[global]
Instance CRabs_morph
  : forall {R : ConstructiveReals},
    CMorphisms.Proper
      (CMorphisms.respectful (CReq R) (CReq R)) (CRabs R).Add Parametric Morphism {R : ConstructiveReals} : (CRabs R)
    with signature CReq R ==> CReq R
      as CRabs_morph_prop.

Lemma CRabs_triang_inv : forall {R : ConstructiveReals} (x y : CRcarrier R), CRabs R x - CRabs R y <= CRabs R (x - y).