Isabelle NEWS -- history of user-visible changes
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New in Isabelle???? (DATE ????)
-------------------------------
*** General Changes ***
* hierachically structured name spaces (for consts, types, axms,
etc.); new lexical class 'longid' (e.g. Foo.bar.x) may render much of
old input syntactically incorrect (e.g. "%x.x"); COMPATIBILITY:
isatool fixdots ensures space after dots (e.g. "%x. x"); set
long_names for fully qualified output names; NOTE: in case of severe
problems with backward campatibility try setting 'global_names' at
compile time to disable qualified names for theories; may also fine
tune theories via 'global' and 'local' section;
* reimplemented the implicit simpset and claset using the new anytype
data filed in signatures; references simpset:simpset ref etc. are
replaced by functions simpset:unit->simpset and
simpset_ref:unit->simpset ref; COMPATIBILITY: use isatool fixclasimp
to patch your ML files accordingly;
* HTML output now includes theory graph data for display with Java
applet or isatool browser; data generated automatically via isatool
usedir (see -i option, ISABELLE_USEDIR_OPTIONS);
* defs may now be conditional; improved rewrite_goals_tac to handle
conditional equations;
* theory aliases via merge (e.g. M=A+B+C) no longer supported, always
creates a new theory node; implicit merge of thms' signatures is
restricted to 'trivial' ones; COMPATIBILITY: one may have to use
transfer:theory->thm->thm in (rare) cases;
* improved handling of draft signatures / theories; draft thms (and
ctyps, cterms) are automatically promoted to real ones;
* slightly changed interfaces for oracles: admit many per theory, named
(e.g. oracle foo = mlfun), additional name argument for invoke_oracle;
* print_goals: optional output of const types (set show_consts and
show_types);
* improved output of warnings (###) / errors (***);
* removed old README and Makefiles;
* replaced print_goals_ref hook by print_current_goals_fn and result_error_fn;
* removed obsolete init_pps and init_database;
* deleted the obsolete tactical STATE, which was declared by
fun STATE tacfun st = tacfun st st;
*** Classical Reasoner ***
* Clarify_tac, clarify_tac, clarify_step_tac, Clarify_step_tac: new
tactics that use classical reasoning to simplify a subgoal without
splitting it into several subgoals;
* Safe_tac: like safe_tac but uses the default claset;
*** Simplifier ***
* added simplification meta rules:
(asm_)(full_)simplify: simpset -> thm -> thm;
* simplifier.ML no longer part of Pure -- has to be loaded by object
logics (again);
* added prems argument to simplification procedures;
*** Syntax ***
* no longer handles consts with name "" -- declare as 'syntax' instead;
* pretty printer: changed order of mixfix annotation preference (again!);
* Pure: fixed idt/idts vs. pttrn/pttrns syntactic categories;
*** HOL ***
* HOL/TLA: Stephan Merz's formalization of Lamport's Temporal Logic of Actions;
* HOL/Auth: new protocol proofs including some for the Internet
protocol TLS;
* HOL/Map: new theory of `maps' a la VDM.
* HOL/simplifier: added infix function `addsplits':
instead of `<simpset> setloop (split_tac <thms>)'
you can simply write `<simpset> addsplits <thms>'
* HOL/simplifier: terms of the form
`? x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x)' (or t=x)
are rewritten to
`P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t)',
and those of the form
`! x. P1(x) & ... & Pn(x) & x=t & Q1(x) & ... Qn(x) --> R(x)' (or t=x)
are rewritten to
`P1(t) & ... & Pn(t) & Q1(t) & ... Qn(t) --> R(t)',
* HOL/datatype
Each datatype `t' now comes with a theorem `split_t_case' 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))
)
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.
* HOL/Lists: the function "set_of_list" has been renamed "set"
(and its theorems too);
*** HOLCF ***
* removed "axioms" and "generated by" section
* replaced "ops" section by extended "consts" section, which is capable of
handling the continuous function space "->" directly
* domain package: proves theorems immediately and stores them in the theory
creates hierachical name space
now uses normal mixfix annotations (instead of cinfix...)
minor changes to some names and values (for consistency),
e.g. cases -> casedist, dists_eq -> dist_eqs,
[take_lemma] -> take_lemmas
separator between mutual domain defs: changed "," to "and"
improved handling of sort constraints. Now they have to
appear on the left-hand side of the equations only.
* fixed LAM <x,y,zs>.b syntax;
* added extended adm_tac to simplifier in HOLCF -- can now discharge
adm (%x. P (t x)), where P is chainfinite and t continuous;
*** FOL and ZF ***
* qed_spec_mp, qed_goal_spec_mp, qed_goalw_spec_mp are available, as
in HOL, they strip ALL and --> from proved theorems;
New in Isabelle94-8 (May 1997)
------------------------------
*** General Changes ***
* new utilities to build / run / maintain Isabelle etc. (in parts
still somewhat experimental); old Makefiles etc. still functional;
* new 'Isabelle System Manual';
* INSTALL text, together with ./configure and ./build scripts;
* reimplemented type inference for greater efficiency, better error
messages and clean internal interface;
* prlim command for dealing with lots of subgoals (an easier way of
setting goals_limit);
*** Syntax ***
* 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;
* added token_translation interface (may translate name tokens in
arbitrary ways, dependent on their type (free, bound, tfree, ...) and
the current print_mode); IMPORTANT: user print translation functions
are responsible for marking newly introduced bounds
(Syntax.mark_boundT);
* token translations for modes "xterm" and "xterm_color" that display
names in bold, underline etc. or colors (which requires a color
version of xterm);
* infixes may now be declared with names independent of their syntax;
* added typed_print_translation (like print_translation, but may
access type of constant);
*** Classical Reasoner ***
Blast_tac: a new tactic! It is often more powerful than fast_tac, but has
some limitations. Blast_tac...
+ ignores addss, addbefore, addafter; this restriction is intrinsic
+ ignores elimination rules that don't have the correct format
(the conclusion MUST be a formula variable)
+ ignores types, which can make HOL proofs fail
+ rules must not require higher-order unification, e.g. apply_type in ZF
[message "Function Var's argument not a bound variable" relates to this]
+ its proof strategy is more general but can actually be slower
* substitution with equality assumptions no longer permutes other
assumptions;
* minor changes in semantics of addafter (now called addaltern); renamed
setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
(and access functions for it);
* improved combination of classical reasoner and simplifier:
+ functions for handling clasimpsets
+ improvement of addss: now the simplifier is called _after_ the
safe steps.
+ safe variant of addss called addSss: uses safe simplifications
_during_ the safe steps. It is more complete as it allows multiple
instantiations of unknowns (e.g. with slow_tac).
*** Simplifier ***
* added interface for simplification procedures (functions that
produce *proven* rewrite rules on the fly, depending on current
redex);
* ordering on terms as parameter (used for ordered rewriting);
* new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
* the solver is now split into a safe and an unsafe part.
This should be invisible for the normal user, except that the
functions setsolver and addsolver have been renamed to setSolver and
addSolver; added safe_asm_full_simp_tac;
*** HOL ***
* a generic induction tactic `induct_tac' which works for all datatypes and
also for type `nat';
* a generic case distinction tactic `exhaust_tac' which works for all
datatypes and also for type `nat';
* each datatype comes with a function `size';
* patterns in case expressions allow tuple patterns as arguments to
constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
* primrec now also works with type nat;
* recdef: a new declaration form, allows general recursive functions to be
defined in theory files. See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
* the constant for negation has been renamed from "not" to "Not" to
harmonize with FOL, ZF, LK, etc.;
* HOL/ex/LFilter theory of a corecursive "filter" functional for
infinite lists;
* HOL/Modelcheck demonstrates invocation of model checker oracle;
* HOL/ex/Ring.thy declares cring_simp, which solves equational
problems in commutative rings, using axiomatic type classes for + and *;
* more examples in HOL/MiniML and HOL/Auth;
* more default rewrite rules for quantifiers, union/intersection;
* a new constant `arbitrary == @x.False';
* HOLCF/IOA replaces old HOL/IOA;
* HOLCF changes: derived all rules and arities
+ axiomatic type classes instead of classes
+ typedef instead of faking type definitions
+ eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
+ new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
+ eliminated the types void, one, tr
+ use unit lift and bool lift (with translations) instead of one and tr
+ eliminated blift from Lift3.thy (use Def instead of blift)
all eliminated rules are derived as theorems --> no visible changes ;
*** ZF ***
* ZF now has Fast_tac, Simp_tac and Auto_tac. Union_iff is a now a default
rewrite rule; this may affect some proofs. eq_cs is gone but can be put back
as ZF_cs addSIs [equalityI];
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;
New in Isabelle94-4
-------------------
* greatly reduced space requirements;
* theory files (.thy) no longer require \...\ escapes at line breaks;
* searchable theorem database (see the section "Retrieving theorems" on
page 8 of the Reference Manual);
* new examples, including Grabczewski's monumental case study of the
Axiom of Choice;
* The previous version of HOL renamed to Old_HOL;
* The new version of HOL (previously called CHOL) uses a curried syntax
for functions. Application looks like f a b instead of f(a,b);
* Mutually recursive inductive definitions finally work in HOL;
* In ZF, pattern-matching on tuples is now available in all abstractions and
translates to the operator "split";
New in Isabelle94-3
-------------------
* new infix operator, addss, allowing the classical reasoner to
perform simplification at each step of its search. Example:
fast_tac (cs addss ss)
* a new logic, CHOL, the same as HOL, but with a curried syntax
for functions. Application looks like f a b instead of f(a,b). Also pairs
look like (a,b) instead of <a,b>;
* PLEASE NOTE: CHOL will eventually replace HOL!
* In CHOL, pattern-matching on tuples is now available in all abstractions.
It translates to the operator "split". A new theory of integers is available;
* In ZF, integer numerals now denote two's-complement binary integers.
Arithmetic operations can be performed by rewriting. See ZF/ex/Bin.ML;
* Many new examples: I/O automata, Church-Rosser theorem, equivalents
of the Axiom of Choice;
New in Isabelle94-2
-------------------
* Significantly faster resolution;
* the different sections in a .thy file can now be mixed and repeated
freely;
* Database of theorems for FOL, HOL and ZF. New
commands including qed, qed_goal and bind_thm store theorems in the database.
* Simple database queries: return a named theorem (get_thm) or all theorems of
a given theory (thms_of), or find out what theory a theorem was proved in
(theory_of_thm);
* Bugs fixed in the inductive definition and datatype packages;
* The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
and HOL_dup_cs obsolete;
* Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
have been removed;
* Simpler definition of function space in ZF;
* new results about cardinal and ordinal arithmetic in ZF;
* 'subtype' facility in HOL for introducing new types as subsets of existing
types;
$Id$