proposition: Lemma modzMDl p m d : (p * d + m = m %[mod d])%Z.
proof: Proof. have [-> | d_nz] := eqVneq d 0; first by rewrite mulr0 add0r. by rewrite /modz divzMDl // mulrDl opprD addrACA subrr add0r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(div choice fintype tuple finfun bigop prime order) mathcomp(ssralg poly ssrnum ssrint archimedean rat matrix) mathcomp(polydiv perm zmodp mxalgebra vector)