Isabelle NEWS -- history of user-visible changes
================================================
New in Isabelle94-8 (??????????? 1997 FIXME)
---------------------------------------
* the NEWS file;
* new utilities to build / run / maintain Isabelle etc. (in parts
still somewhat experimental); old Makefiles etc. still functional;
* simplifier: termless order as parameter; added interface for
simplification procedures (functions that produce *proven* rewrite
rules on the fly, depending on current redex);
* now supports alternative (named) syntax tables (parser and pretty
printer); internal interface is provided by add_modesyntax(_i);
* Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
be used in conjunction with the isabelle symbol font; uses the
"symbols" syntax table;
* infixes may now be declared with names independent of their syntax;
* added typed_print_translation (like print_translation, but may
access type of constant);
* prlim command for dealing with lots of subgoals (an easier way of
setting goals_limit);
* HOL/ex/Ring.thy declares cring_simp, which solves equational
problems in commutative rings, using axiomatic type classes for + and *;
* ZF now has Fast_tac, Simp_tac and Auto_tac. WARNING: don't use
ZF.thy anymore! Contains fewer defs and could make a bogus simpset.
Beware of Union_iff. eq_cs is gone, can be put back as ZF_cs addSIs
[equalityI];
* more examples in HOL/MiniML and HOL/Auth;
* more default rewrite rules in HOL for quantifiers, union/intersection;
New in Isabelle94-7 (November 96)
---------------------------------
* allowing negative levels (as offsets) in prlev and choplev;
* super-linear speedup for large simplifications;
* FOL, ZF and HOL now use miniscoping: rewriting pushes
quantifications in as far as possible (COULD MAKE EXISTING PROOFS
FAIL); can suppress it using the command Delsimps (ex_simps @
all_simps); De Morgan laws are also now included, by default;
* improved printing of ==> : ~:
* new object-logic "Sequents" adds linear logic, while replacing LK
and Modal (thanks to Sara Kalvala);
* HOL/Auth: correctness proofs for authentication protocols;
* HOL: new auto_tac combines rewriting and classical reasoning (many
examples on HOL/Auth);
* HOL: new command AddIffs for declaring theorems of the form P=Q to
the rewriter and classical reasoner simultaneously;
* function uresult no longer returns theorems in "standard" format;
regain previous version by: val uresult = standard o uresult;
New in Isabelle94-6
-------------------
* oracles -- these establish an interface between Isabelle and trusted
external reasoners, which may deliver results as theorems;
* proof objects (in particular record all uses of oracles);
* Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
* "constdefs" section in theory files;
* "primrec" section (HOL) no longer requires names;
* internal type "tactic" now simply "thm -> thm Sequence.seq";
New in Isabelle94-5
-------------------
* reduced space requirements;
* automatic HTML generation from theories;
* theory files no longer require "..." (quotes) around most types;
* new examples, including two proofs of the Church-Rosser theorem;
* non-curried (1994) version of HOL is no longer distributed;
$Id$