Fact Cnat_key : pred_key Cnat.Fact Cnat_semiring : semiring_closed Cnat.Canonical Cnat_keyed := KeyedPred Cnat_key.Canonical Cnat_addrPred := AddrPred Cnat_semiring.Canonical Cnat_mulrPred := MulrPred Cnat_semiring.Canonical Cnat_semiringPred := SemiringPred Cnat_semiring.

Lemma Creal_Cnat : {subset Cnat <= Creal}.