NEWS
author paulson
Mon May 26 12:34:54 1997 +0200 (1997-05-26)
changeset 3338 b99d750f6a37
parent 3321 c609a0119fd8
child 3454 40b1287347d7
permissions -rw-r--r--
Added recdef
     1 
     2 Isabelle NEWS -- history of user-visible changes
     3 ================================================
     4 
     5 New in Isabelle94-8 (May 1997)
     6 ------------------------------
     7 
     8 *** General Changes ***
     9 
    10 * new utilities to build / run / maintain Isabelle etc. (in parts
    11 still somewhat experimental); old Makefiles etc. still functional;
    12 
    13 * new 'Isabelle System Manual';
    14 
    15 * INSTALL text, together with ./configure and ./build scripts;
    16 
    17 * reimplemented type inference for greater efficiency, better error
    18 messages and clean internal interface;
    19 
    20 * prlim command for dealing with lots of subgoals (an easier way of
    21 setting goals_limit);
    22 
    23 
    24 *** Syntax ***
    25 
    26 * supports alternative (named) syntax tables (parser and pretty
    27 printer); internal interface is provided by add_modesyntax(_i);
    28 
    29 * Pure, FOL, ZF, HOL, HOLCF now support symbolic input and output; to
    30 be used in conjunction with the Isabelle symbol font; uses the
    31 "symbols" syntax table;
    32 
    33 * added token_translation interface (may translate name tokens in
    34 arbitrary ways, dependent on their type (free, bound, tfree, ...) and
    35 the current print_mode); IMPORTANT: user print translation functions
    36 are responsible for marking newly introduced bounds
    37 (Syntax.mark_boundT);
    38 
    39 * token translations for modes "xterm" and "xterm_color" that display
    40 names in bold, underline etc. or colors (which requires a color
    41 version of xterm);
    42 
    43 * infixes may now be declared with names independent of their syntax;
    44 
    45 * added typed_print_translation (like print_translation, but may
    46 access type of constant);
    47 
    48 
    49 *** Classical Reasoner ***
    50 
    51 Blast_tac: a new tactic!  It is often more powerful than fast_tac, but has
    52 some limitations.  Blast_tac...
    53   + ignores addss, addbefore, addafter; this restriction is intrinsic
    54   + ignores elimination rules that don't have the correct format
    55 	(the conclusion MUST be a formula variable)
    56   + ignores types, which can make HOL proofs fail
    57   + rules must not require higher-order unification, e.g. apply_type in ZF
    58     [message "Function Var's argument not a bound variable" relates to this]
    59   + its proof strategy is more general but can actually be slower
    60 
    61 * substitution with equality assumptions no longer permutes other
    62 assumptions;
    63 
    64 * minor changes in semantics of addafter (now called addaltern); renamed
    65 setwrapper to setWrapper and compwrapper to compWrapper; added safe wrapper
    66 (and access functions for it);
    67 
    68 * improved combination of classical reasoner and simplifier: 
    69   + functions for handling clasimpsets
    70   + improvement of addss: now the simplifier is called _after_ the
    71     safe steps.
    72   + safe variant of addss called addSss: uses safe simplifications
    73     _during_ the safe steps. It is more complete as it allows multiple 
    74     instantiations of unknowns (e.g. with slow_tac).
    75 
    76 *** Simplifier ***
    77 
    78 * added interface for simplification procedures (functions that
    79 produce *proven* rewrite rules on the fly, depending on current
    80 redex);
    81 
    82 * ordering on terms as parameter (used for ordered rewriting);
    83 
    84 * new functions delcongs, deleqcongs, and Delcongs. richer rep_ss;
    85 
    86 * the solver is now split into a safe and an unsafe part.
    87 This should be invisible for the normal user, except that the
    88 functions setsolver and addsolver have been renamed to setSolver and
    89 addSolver; added safe_asm_full_simp_tac;
    90 
    91 
    92 *** HOL ***
    93 
    94 * a generic induction tactic `induct_tac' which works for all datatypes and
    95 also for type `nat';
    96 
    97 * a generic case distinction tactic `exhaust_tac' which works for all
    98 datatypes and also for type `nat';
    99 
   100 * each datatype comes with a function `size';
   101 
   102 * patterns in case expressions allow tuple patterns as arguments to
   103 constructors, for example `case x of [] => ... | (x,y,z)#ps => ...';
   104 
   105 * primrec now also works with type nat;
   106 
   107 * recdef: a new declaration form, allows general recursive functions to be
   108 defined in theory files.  See HOL/ex/Fib, HOL/ex/Primes, HOL/Subst/Unify.
   109 
   110 * the constant for negation has been renamed from "not" to "Not" to
   111 harmonize with FOL, ZF, LK, etc.;
   112 
   113 * HOL/ex/LFilter theory of a corecursive "filter" functional for
   114 infinite lists;
   115 
   116 * HOL/Modelcheck demonstrates invocation of model checker oracle;
   117 
   118 * HOL/ex/Ring.thy declares cring_simp, which solves equational
   119 problems in commutative rings, using axiomatic type classes for + and *;
   120 
   121 * more examples in HOL/MiniML and HOL/Auth;
   122 
   123 * more default rewrite rules for quantifiers, union/intersection;
   124 
   125 * a new constant `arbitrary == @x.False';
   126 
   127 * HOLCF/IOA replaces old HOL/IOA;
   128 
   129 * HOLCF changes: derived all rules and arities 
   130   + axiomatic type classes instead of classes 
   131   + typedef instead of faking type definitions
   132   + eliminated the internal constants less_fun, less_cfun, UU_fun, UU_cfun etc.
   133   + new axclasses cpo, chfin, flat with flat < chfin < pcpo < cpo < po
   134   + eliminated the types void, one, tr
   135   + use unit lift and bool lift (with translations) instead of one and tr
   136   + eliminated blift from Lift3.thy (use Def instead of blift)
   137   all eliminated rules are derived as theorems --> no visible changes ;
   138 
   139 
   140 *** ZF ***
   141 
   142 * ZF now has Fast_tac, Simp_tac and Auto_tac.  Union_iff is a now a default
   143 rewrite rule; this may affect some proofs.  eq_cs is gone but can be put back
   144 as ZF_cs addSIs [equalityI];
   145 
   146 
   147 
   148 New in Isabelle94-7 (November 96)
   149 ---------------------------------
   150 
   151 * allowing negative levels (as offsets) in prlev and choplev;
   152 
   153 * super-linear speedup for large simplifications;
   154 
   155 * FOL, ZF and HOL now use miniscoping: rewriting pushes
   156 quantifications in as far as possible (COULD MAKE EXISTING PROOFS
   157 FAIL); can suppress it using the command Delsimps (ex_simps @
   158 all_simps); De Morgan laws are also now included, by default;
   159 
   160 * improved printing of ==>  :  ~:
   161 
   162 * new object-logic "Sequents" adds linear logic, while replacing LK
   163 and Modal (thanks to Sara Kalvala);
   164 
   165 * HOL/Auth: correctness proofs for authentication protocols;
   166 
   167 * HOL: new auto_tac combines rewriting and classical reasoning (many
   168 examples on HOL/Auth);
   169 
   170 * HOL: new command AddIffs for declaring theorems of the form P=Q to
   171 the rewriter and classical reasoner simultaneously;
   172 
   173 * function uresult no longer returns theorems in "standard" format;
   174 regain previous version by: val uresult = standard o uresult;
   175 
   176 
   177 
   178 New in Isabelle94-6
   179 -------------------
   180 
   181 * oracles -- these establish an interface between Isabelle and trusted
   182 external reasoners, which may deliver results as theorems;
   183 
   184 * proof objects (in particular record all uses of oracles);
   185 
   186 * Simp_tac, Fast_tac, etc. that refer to implicit simpset / claset;
   187 
   188 * "constdefs" section in theory files;
   189 
   190 * "primrec" section (HOL) no longer requires names;
   191 
   192 * internal type "tactic" now simply "thm -> thm Sequence.seq";
   193 
   194 
   195 
   196 New in Isabelle94-5
   197 -------------------
   198 
   199 * reduced space requirements;
   200 
   201 * automatic HTML generation from theories;
   202 
   203 * theory files no longer require "..." (quotes) around most types;
   204 
   205 * new examples, including two proofs of the Church-Rosser theorem;
   206 
   207 * non-curried (1994) version of HOL is no longer distributed;
   208 
   209 
   210 
   211 New in Isabelle94-4
   212 -------------------
   213 
   214 * greatly reduced space requirements;
   215 
   216 * theory files (.thy) no longer require \...\ escapes at line breaks;
   217 
   218 * searchable theorem database (see the section "Retrieving theorems" on 
   219 page 8 of the Reference Manual);
   220 
   221 * new examples, including Grabczewski's monumental case study of the
   222 Axiom of Choice;
   223 
   224 * The previous version of HOL renamed to Old_HOL;
   225 
   226 * The new version of HOL (previously called CHOL) uses a curried syntax 
   227 for functions.  Application looks like f a b instead of f(a,b);
   228 
   229 * Mutually recursive inductive definitions finally work in HOL;
   230 
   231 * In ZF, pattern-matching on tuples is now available in all abstractions and
   232 translates to the operator "split";
   233 
   234 
   235 
   236 New in Isabelle94-3
   237 -------------------
   238 
   239 * new infix operator, addss, allowing the classical reasoner to 
   240 perform simplification at each step of its search.  Example:
   241 	fast_tac (cs addss ss)
   242 
   243 * a new logic, CHOL, the same as HOL, but with a curried syntax 
   244 for functions.  Application looks like f a b instead of f(a,b).  Also pairs 
   245 look like (a,b) instead of <a,b>;
   246 
   247 * PLEASE NOTE: CHOL will eventually replace HOL!
   248 
   249 * In CHOL, pattern-matching on tuples is now available in all abstractions.
   250 It translates to the operator "split".  A new theory of integers is available;
   251 
   252 * In ZF, integer numerals now denote two's-complement binary integers.
   253 Arithmetic operations can be performed by rewriting.  See ZF/ex/Bin.ML;
   254 
   255 * Many new examples: I/O automata, Church-Rosser theorem, equivalents 
   256 of the Axiom of Choice;
   257 
   258 
   259 
   260 New in Isabelle94-2
   261 -------------------
   262 
   263 * Significantly faster resolution;  
   264 
   265 * the different sections in a .thy file can now be mixed and repeated
   266 freely;
   267 
   268 * Database of theorems for FOL, HOL and ZF.  New
   269 commands including qed, qed_goal and bind_thm store theorems in the database.
   270 
   271 * Simple database queries: return a named theorem (get_thm) or all theorems of
   272 a given theory (thms_of), or find out what theory a theorem was proved in
   273 (theory_of_thm);
   274 
   275 * Bugs fixed in the inductive definition and datatype packages;
   276 
   277 * The classical reasoner provides deepen_tac and depth_tac, making FOL_dup_cs
   278 and HOL_dup_cs obsolete;
   279 
   280 * Syntactic ambiguities caused by the new treatment of syntax in Isabelle94-1
   281 have been removed;
   282 
   283 * Simpler definition of function space in ZF;
   284 
   285 * new results about cardinal and ordinal arithmetic in ZF;
   286 
   287 * 'subtype' facility in HOL for introducing new types as subsets of existing
   288 types;
   289 
   290 
   291 $Id$