Identity Coercion type_fracdomain_of : ratio_of >-> ratio.Local Notation frac := (R * R).Local Notation dom := (ratio R).Local Notation domP := denom_ratioP.Implicit Types x y z : dom.Definition equivf x y := equivf_notation x y.

(* Specifications: *)
Lemma equivfE x y : equivf x y = equivf_notation x y.
Lemma equivf_refl : reflexive equivf.
Lemma equivf_sym : symmetric equivf.
Lemma equivf_trans : transitive equivf.