Canonical Qnat_addrPred := AddrPred Qnat_semiring_closed.
Canonical Qnat_mulrPred := MulrPred Qnat_semiring_closed.
Canonical Qnat_semiringPred := SemiringPred Qnat_semiring_closed.
End QnatPred.

(* Specifications: *)
Lemma natq_div m n : n %| m -> (m %/ n)%:R = m%:R / n%:R :> rat.
Lemma rat_lrmorphism A B (f : A -> B) : rmorphism f -> lrmorphism f.
Canonical ratr_additive := Additive ratr_is_rmorphism.