Canonical dvdA_opprPred e := OpprPred (dvdA_zmod_closed e).
Canonical dvdA_addrPred e := AddrPred (dvdA_zmod_closed e).
Canonical dvdA_zmodPred e := ZmodPred (dvdA_zmod_closed e).
Definition eqAmod (e x y : Algebraics.divisor) := (e %| x - y)%A.
Notation "x == y %[mod e ]" := (eqAmod e x y) : algC_scope.
Notation "x != y %[mod e ]" := (~~ (eqAmod e x y)) : algC_scope.

Lemma eqAmodMl e :
{in Aint, forall z x y, x == y %[mod e] -> z * x == z * y %[mod e]}%A.