Canonical Cint_opprPred := OpprPred Cint_subring.
Canonical Cint_addrPred := AddrPred Cint_subring.
Canonical Cint_mulrPred := MulrPred Cint_subring.
Canonical Cint_zmodPred := ZmodPred Cint_subring.
Canonical Cint_semiringPred := SemiringPred Cint_subring.
Canonical Cint_smulrPred := SmulrPred Cint_subring.
Canonical Cint_subringPred := SubringPred Cint_subring.

Lemma truncC0Pn x : reflect (truncC x = 0%N) (~~ (1 <= x)).