X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fbasic_2%2Fstatic%2Fffdeq_ffdeq.ma;h=10146360997f7b0042631d151d58ca9f1f4bae2c;hp=47a38804ce2537f86fa22146cea00f0b4eea0148;hb=9323611e3819c1382b872a7ada00264991f36217;hpb=b0eb62e60a2fd73ba39c7a0df112f04131528602

diff --git a/matita/matita/contribs/lambdadelta/basic_2/static/ffdeq_ffdeq.ma b/matita/matita/contribs/lambdadelta/basic_2/static/ffdeq_ffdeq.ma
index 47a38804c..101463609 100644
--- a/matita/matita/contribs/lambdadelta/basic_2/static/ffdeq_ffdeq.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/static/ffdeq_ffdeq.ma
@@ -17,6 +17,12 @@ include "basic_2/static/ffdeq.ma".
 
 (* DEGREE-BASED EQUIVALENCE FOR CLOSURES ON REFERRED ENTRIES ****************)
 
+(* Advanced properties ******************************************************)
+
+lemma ffdeq_sym: ∀h,o. tri_symmetric … (ffdeq h o).
+#h #o #G1 #G2 #L1 #L2 #T1 #T2 * -G1 -L1 -T1 /3 width=1 by ffdeq_intro, lfdeq_sym/
+qed-.
+
 (* Main properties **********************************************************)
 
 theorem ffdeq_trans: ∀h,o. tri_transitive … (ffdeq h o).