proposition: Lemma natr_mod_char n : (n %% p)%:R = n%:R :> R.
proof: Proof. by rewrite {2}(divn_eq n p) natrD mulrnA mulrn_char add0r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)