proposition: Lemma dec_recip_nonzero_aux@{} : forall q, ' q <> 0 -> num q <> 0.
proof: Proof. intros q E;apply classes_neq_related in E. apply Frac.nonzero_num in E. trivial. Qed.
imports: HoTT.HIT.quotient HoTT.Basics.Trunc HoTT.Classes.interfaces.abstract_algebra HoTT.Classes.theory.dec_fields