--- a/NEWS Fri Nov 07 18:02:15 1997 +0100
+++ b/NEWS Fri Nov 07 18:05:25 1997 +0100
@@ -95,6 +95,9 @@
*** HOL ***
+* HOL: there is a new splitter `split_prem_tac' that can be used e.g.
+ with `addloop' of the simplifier to faciliate case splitting in premises.
+
* HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
* HOL/Auth: new protocol proofs including some for the Internet
@@ -121,13 +124,23 @@
P(t_case f1 ... fn x) =
( (!y1 ... ym1. x = C1 y1 ... ym1 --> P(f1 y1 ... ym1)) &
...
- (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
+ (!y1 ... ymn. x = Cn y1 ... ymn --> P(f1 y1 ... ymn))
)
which can be added to a simpset via `addsplits'. The existing theorems
expand_list_case and expand_option_case have been renamed to
split_list_case and split_option_case.
+ Additionally, there is a theorem `split_t_case_prem' of the form
+
+ P(t_case f1 ... fn x) =
+ ~( (? y1 ... ym1. x = C1 y1 ... ym1 & ~P(f1 y1 ... ym1)) |
+ ...
+ (? y1 ... ymn. x = Cn y1 ... ymn & ~P(f1 y1 ... ymn))
+ )
+
+ it be used with the new `split_prem_tac'.
+
* HOL/Lists: the function "set_of_list" has been renamed "set"
(and its theorems too);
@@ -162,6 +175,9 @@
*** FOL and ZF ***
+* FOL: there is a new splitter `split_prem_tac' that can be used e.g.
+ with `addloop' of the simplifier to faciliate case splitting in premises.
+
* qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
in HOL, they strip ALL and --> from proved theorems;