X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fbasic_2%2Fstatic%2Ffrees_append.ma;h=9cf6bfe1959abddebfa34ce867c0b7bcb637ac43;hp=56205c3db360c832b67c7f9da216ce9d0f4fa791;hb=222044da28742b24584549ba86b1805a87def070;hpb=47a745462a714af9d65cea7b61af56524bd98fa1

diff --git a/matita/matita/contribs/lambdadelta/basic_2/static/frees_append.ma b/matita/matita/contribs/lambdadelta/basic_2/static/frees_append.ma
index 56205c3db..9cf6bfe19 100644
--- a/matita/matita/contribs/lambdadelta/basic_2/static/frees_append.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/static/frees_append.ma
@@ -19,7 +19,7 @@ include "basic_2/static/frees.ma".
 
 (* Properties with append for local environments ****************************)
 
-lemma frees_append_void: ∀f,K,T. K ⊢ 𝐅*⦃T⦄ ≡ f → ⓧ.K ⊢ 𝐅*⦃T⦄ ≡ f.
+lemma frees_append_void: ∀f,K,T. K ⊢ 𝐅*⦃T⦄ ≘ f → ⓧ.K ⊢ 𝐅*⦃T⦄ ≘ f.
 #f #K #T #H elim H -f -K -T
 [ /2 width=1 by frees_sort/
 | #f * /3 width=1 by frees_atom, frees_unit, frees_lref/
@@ -34,8 +34,8 @@ qed.
 
 (* Inversion lemmas with append for local environments **********************)
 
-fact frees_inv_append_void_aux: ∀f,L,T. L ⊢ 𝐅*⦃T⦄ ≡ f →
-                                ∀K. L = ⓧ.K → K ⊢ 𝐅*⦃T⦄ ≡ f.
+fact frees_inv_append_void_aux: ∀f,L,T. L ⊢ 𝐅*⦃T⦄ ≘ f →
+                                ∀K. L = ⓧ.K → K ⊢ 𝐅*⦃T⦄ ≘ f.
 #f #L #T #H elim H -f -L -T
 [ /2 width=1 by frees_sort/
 | #f #i #_ #K #H 
@@ -55,5 +55,5 @@ fact frees_inv_append_void_aux: ∀f,L,T. L ⊢ 𝐅*⦃T⦄ ≡ f →
 ]
 qed-.
 
-lemma frees_inv_append_void: ∀f,K,T. ⓧ.K  ⊢ 𝐅*⦃T⦄ ≡ f → K ⊢ 𝐅*⦃T⦄ ≡ f.
+lemma frees_inv_append_void: ∀f,K,T. ⓧ.K  ⊢ 𝐅*⦃T⦄ ≘ f → K ⊢ 𝐅*⦃T⦄ ≘ f.
 /2 width=3 by frees_inv_append_void_aux/ qed-.