#[global]
Instance CR_of_Q_morph_T
: forall {R : ConstructiveReals}, CMorphisms.Proper
(CMorphisms.respectful Qeq (CReq R)) (CR_of_Q R).

Lemma CRmult_le_reg_l :
forall {R : ConstructiveReals} (x y z : CRcarrier R),
0 < x -> x * y <= x * z -> y <= z.