advances non lfsx ...

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / static / lfxs.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/static/lfxs.ma b/matita/matita/contribs/lambdadelta/basic_2/static/lfxs.ma
index 9f0a1a4865522b6c685acbf242e721c207a2027a..1d7781d7e8adc0e648736ab2bf3664f51a1bb293 100644 (file)
--- a/matita/matita/contribs/lambdadelta/basic_2/static/lfxs.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/static/lfxs.ma
@@ -89,13 +89,21 @@ lemma lfxs_co: ∀R1,R2. (∀L,T1,T2. R1 L T1 T2 → R2 L T1 T2) →
 #R1 #R2 #HR #L1 #L2 #T * /4 width=7 by lexs_co, ex2_intro/
 qed-.
 
+lemma lfxs_isid: ∀R1,R2,L1,L2,T1,T2.
+                 (∀f. L1 ⊢ 𝐅*⦃T1⦄ ≡ f → 𝐈⦃f⦄) → 
+                 (∀f. 𝐈⦃f⦄ → L1 ⊢ 𝐅*⦃T2⦄ ≡ f) → 
+                 L1 ⦻*[R1, T1] L2 → L1 ⦻*[R2, T2] L2.
+#R1 #R2 #L1 #L2 #T1 #T2 #H1 #H2 *
+/4 width=7 by lexs_co_isid, ex2_intro/
+qed-.
+
 (* Basic inversion lemmas ***************************************************)
 
-lemma lfxs_inv_atom_sn: ∀R,I,Y2. ⋆ ⦻*[R, ⓪{I}] Y2 → Y2 = ⋆.
-#R #I #Y2 * /2 width=4 by lexs_inv_atom1/
+lemma lfxs_inv_atom_sn: ∀R,Y2,T. ⋆ ⦻*[R, T] Y2 → Y2 = ⋆.
+#R #Y2 #T * /2 width=4 by lexs_inv_atom1/
 qed-.
 
-lemma lfxs_inv_atom_dx: ∀R,I,Y1. Y1 ⦻*[R, ⓪{I}] ⋆ → Y1 = ⋆.
+lemma lfxs_inv_atom_dx: ∀R,Y1,T. Y1 ⦻*[R, T] ⋆ → Y1 = ⋆.
 #R #I #Y1 * /2 width=4 by lexs_inv_atom2/
 qed-.