--- a/NEWS Wed Jun 13 11:16:24 2007 +0200
+++ b/NEWS Wed Jun 13 11:54:03 2007 +0200
@@ -154,6 +154,21 @@
Command 'print_theory' outputs the normalized system of recursive
equations, see section "definitions".
+* Isar: method "assumption" (and implicit closing of subproofs) now
+takes simple non-atomic goal assumptions into account: after applying
+an assumption as a rule the resulting subgoals are solved by atomic
+assumption steps. This is particularly useful to finish 'obtain'
+goals, such as "!!x. (!!x. P x ==> thesis) ==> P x ==> thesis",
+without referring to the original premise "!!x. P x ==> thesis" in the
+Isar proof context. POTENTIAL INCOMPATIBILITY: method "assumption" is
+more permissive.
+
+* Isar: implicit use of prems from the Isar proof context is
+considered a legacy feature. Common applications like ``have A .''
+may be replaced by ``have A by fact'' or ``note `A`''. In general,
+referencing facts explicitly here improves readability and
+maintainability of proof texts.
+
* Isar: improper proof element 'guess' is like 'obtain', but derives
the obtained context from the course of reasoning! For example: