update in basic_2

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / web / basic_2.ldw.xml

diff --git a/matita/matita/contribs/lambdadelta/basic_2/web/basic_2.ldw.xml b/matita/matita/contribs/lambdadelta/basic_2/web/basic_2.ldw.xml
index a5c53bf3e17a212da07212849aec0276de36e8a5..28575ff0ea587c7a0b377529bd7140048bd6c21e 100644 (file)
--- a/matita/matita/contribs/lambdadelta/basic_2/web/basic_2.ldw.xml
+++ b/matita/matita/contribs/lambdadelta/basic_2/web/basic_2.ldw.xml
@@ -27,8 +27,17 @@
    <table name="basic_2_sum"/>
 
    <subsection name="B">Stage "B"</subsection>
+   <news class="beta" date="2019 September 3.">
+         Applicability condition is now parametrized
+         with a generic subset of numbers.
+   </news>
+   <news class="beta" date="2019 June 2.">
+         Applicability condition parametrized
+         with an initial interval of numbers
+         allows λδ-2B to generalize both λδ-2A and λδ-1B.
+   </news>
    <news class="beta" date="2019 April 16.">
-         Extended (λδ-2) and restricted (λδ-1) validity is decidable 
+         Extended (λδ-2A) and restricted (λδ-1B) validity is decidable
          (anniversary milestone).
    </news>
    <news class="beta" date="2019 March 25.">
@@ -37,7 +46,7 @@
          (i.e. no induction on the degree).
    </news>
    <news class="beta" date="2018 November 1.">
-         Extended (λδ-2) and restricted (λδ-1) type rules justified.
+         Extended (λδ-2A) and restricted (λδ-1B) validity rules justified.
    </news>
    <news class="alpha" date="2018 September 21.">
          λδ-2A completed with
@@ -93,7 +102,7 @@
          λδ-2A appears too complex and is dismissed.
    </news>
    <news class="gamma" date="2014 October 28.">
-         λδ version 2A is released.
+         λδ-2A is released.
    </news>
    <news class="beta" date="2014 September 9.">
          Iterated static type assignment defined (more elegantly)