X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambda_delta%2Fbasic_2%2Fgrammar%2Faarity.ma;h=2f5f7b4950195796eb4f900a283fd9eef97fe419;hb=5ea90cbbb01fe0bf3b77221d9e6c87002982621f;hp=0d7db6beb8bbd5ba996ab06b480b100ff7564628;hpb=de64015de66a48373ade6cab7508d8f8e2c43af9;p=helm.git

diff --git a/matita/matita/contribs/lambda_delta/basic_2/grammar/aarity.ma b/matita/matita/contribs/lambda_delta/basic_2/grammar/aarity.ma
index 0d7db6beb..2f5f7b495 100644
--- a/matita/matita/contribs/lambda_delta/basic_2/grammar/aarity.ma
+++ b/matita/matita/contribs/lambda_delta/basic_2/grammar/aarity.ma
@@ -13,14 +13,20 @@
 (**************************************************************************)
 
 (* THE FORMAL SYSTEM λδ: MATITA SOURCE FILES
- * - Patience on me to gain peace and perfection! -
- * [ suggested invocation to start formal specifications with ]
- * Context-sensitive subject equivalence for atomic arity assignment: 2012 April 16
- * Context-sensitive strong normalization for simply typed terms: 2012 March 15
- * Support for abstract candidates of reducibility closed: 2012 January 27
- * Confluence for context-sensitive parallel reduction: 2011 September 21
- * Confluence for context-free parallel reduction: 2011 September 6
- * Specification starts: 2011 April 17
+ * Suggested invocation to start formal specifications with:
+ *   - Patience on me to gain peace and perfection! -
+ * 2012 April 16 (anniversary milestone):
+ *   context-sensitive subject equivalence for atomic arity assignment.
+ * 2012 March 15:
+ *   context-sensitive strong normalization for simply typed terms.
+ * 2012 January 27:
+ *   support for abstract candidates of reducibility.
+ * 2011 September 21:
+ *   confluence for context-sensitive parallel reduction. 
+ * 2011 September 6:
+ *   confluence for context-free parallel reduction.
+ * 2011 April 17:
+ *   specification starts.
  *)
 
 include "ground_2/star.ma".
@@ -41,7 +47,7 @@ interpretation "aarity construction (binary)"
 
 (* Basic inversion lemmas ***************************************************)
 
-lemma discr_apair_xy_x: ∀A,B. ②B. A = B → False.
+lemma discr_apair_xy_x: ∀A,B. ②B. A = B → ⊥.
 #A #B elim B -B
 [ #H destruct
 | #Y #X #IHY #_ #H destruct
@@ -50,7 +56,7 @@ lemma discr_apair_xy_x: ∀A,B. ②B. A = B → False.
 ]
 qed-.
 
-lemma discr_tpair_xy_y: ∀B,A. ②B. A = A → False.
+lemma discr_tpair_xy_y: ∀B,A. ②B. A = A → ⊥.
 #B #A elim A -A
 [ #H destruct
 | #Y #X #_ #IHX #H destruct