proposition: Lemma equivf_def (x y : ratio R) : x == y %[mod type] = (\n_x * \d_y == \d_x * \n_y).
proof: Proof. by rewrite eqmodE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(ssrAC choice tuple bigop ssralg poly polydiv) mathcomp(generic_quotient)