coercion cic:/matita/excedence/eq_symmetric_.con.
-lemma eq_transitive: ∀E.transitive ? (eq E).
+lemma eq_transitive_: ∀E.transitive ? (eq E).
(* bug. intros k deve fare whd quanto basta *)
intros 6 (E x y z Exy Eyz); intro Axy; cases (ap_cotransitive ???y Axy);
[apply Exy|apply Eyz] assumption.
qed.
+lemma eq_transitive:∀E:apartness.∀x,y,z:E.x ≈ y → y ≈ z → x ≈ z ≝ eq_transitive_.
+
(* BUG: vedere se ricapita *)
lemma le_antisymmetric: ∀E.antisymmetric ? (le E) (eq ?).
intros 5 (E x y Lxy Lyx); intro H;