proposition: Lemma Qrat_to_intK : cancel rat_to_Qint Qint_to_rat.
proof: Proof. by move=> x; rewrite /Qint_to_rat /= absz_denq divq_num_den. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq zmodp) mathcomp(path choice fintype tuple finset bigop order) mathcomp(ssralg ssrint ssrnum rat) CoqEAL(hrel param refinements pos)