Add Parametric Morphism : CReal_mult
    with signature CRealEq ==> CRealEq ==> CRealEq
      as CReal_mult_morph.#[global]
Instance CReal_mult_morph_T
  : CMorphisms.Proper
      (CMorphisms.respectful CRealEq (CMorphisms.respectful CRealEq CRealEq)) CReal_mult.Add Parametric Morphism : CReal_opp
    with signature CRealEq ==> CRealEq
      as CReal_opp_morph.#[global]
Instance CReal_opp_morph_T
  : CMorphisms.Proper
      (CMorphisms.respectful CRealEq CRealEq) CReal_opp.Add Parametric Morphism : CReal_minus
    with signature CRealEq ==> CRealEq ==> CRealEq
      as CReal_minus_morph.#[global]
Instance CReal_minus_morph_T
  : CMorphisms.Proper
      (CMorphisms.respectful CRealEq (CMorphisms.respectful CRealEq CRealEq)) CReal_minus.Add Ring CRealRing : CReal_isRing.

Lemma CReal_abs_appart_zero : forall (x : CReal) (n : Z), (2*2^n < Qabs (seq x n))%Q -> 0 # x.