more work on dama

[helm.git] / helm / software / matita / contribs / dama / dama / supremum.ma

diff --git a/helm/software/matita/contribs/dama/dama/supremum.ma b/helm/software/matita/contribs/dama/dama/supremum.ma
index 757de3e3bf6bc9bfa2bf71b81476291c21d97c8b..715fb5bdbcd5f50f87afaef34b4d27ce48a4222c 100644 (file)
--- a/helm/software/matita/contribs/dama/dama/supremum.ma
+++ b/helm/software/matita/contribs/dama/dama/supremum.ma
@@ -48,6 +48,12 @@ include "bishop_set.ma".
   
 lemma uniq_supremum: 
   ∀O:ordered_set.∀s:sequence O.∀t1,t2:O.
-    t1 is_upper_bound s → t2 is_upper_bound s → t1 ≈ t2.
-intros (O s t1 t2 Ht1 Ht2); apply le_le_eq; cases Ht1; cases Ht2;
+    t1 is_strong_sup s → t2 is_strong_sup s → t1 ≈ t2.
+intros (O s t1 t2 Ht1 Ht2); cases Ht1 (U1 H1); cases Ht2 (U2 H2); 
+apply le_le_eq; intro X;
+[1: cases (H1 ? X); apply (U2 w); assumption
+|2: cases (H2 ? X); apply (U1 w); assumption]
+qed.
+
+