Canonical dvdC_opprPred x := OpprPred (dvdC_zmod x).
Canonical dvdC_addrPred x := AddrPred (dvdC_zmod x).
Canonical dvdC_zmodPred x := ZmodPred (dvdC_zmod x).

Lemma dvdC_nat (p n : nat) : (p %| n)%C = (p %| n)%N.