NEWS 51.9 KB
Newer Older
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1
2
New in spot 1.1.4a (not relased)

3
4
5
  * All the parsers implemented in Spot now use the same type
    to store locations.

6
7
8
  * ltlcross has a new option --color to color its output.  It is enabled
    by default when the output is a terminal.

9
10
11
12
  * ltlcross will give an example of infinite word accepted by the
    two automata when the product between a positive automaton and
    a negative automaton is non-empty.

13
14
15
16
  * Environment variables SPOT_TMPDIR and SPOT_TMPKEEP control where
    temporary files are created and if they should be erased.  Read
    the man page of ltlcross for detail.

17
18
19
  * Degeneralization was not indempotant on automata with an accepting
    initial state that was on a cycle, but without self-loop.

20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
  * Cleanup of exported symbols

    All symbols in the library now have hidden visibility on ELF systems.
    Public classes and functions have been marked explicitely for export
    with the SPOT_API macro.

    During this massive update, some of functions that should not have
    been made public in the first place have been moved away so that
    they can only be used from the library.  Some old of unused
    functions have been removed.

    removed:
      - class loopless_modular_mixed_radix_gray_code

    hidden:
      - class acc_compl
      - class acceptance_convertor
      - class bdd_allocator
      - class free_list
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
39

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
40
New in spot 1.1.4 (2013-07-29)
41

42
43
44
45
46
  * Bug fixes:
    - The parser for neverclaim, updated in 1.1.3, would fail to
      parse guards of the form (a) || (b) output by ltl2ba or
      ltl3ba, and would only understand ((a) || (b)).
    - When used from ltlcross, the same parser would fail to
47
48
      parse further neverclaims after the first failure.
    - Add a missing newline in some error message of ltlcross.
49
50
51
52
53
54
55
    - Expressions like {SERE} were wrongly translated and simplified
      for SEREs that accept the empty word: they were wrongly reduced
      to true.  Simplification and translation rules have been fixed,
      and the doc/tl/tl.pdf specifications have been updated to better
      explain that {SERE} has the semantics of a closure operator that
      is not exactly what one could expect after reading the PSL
      standard.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
56
    - Various typos.
57

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
58
New in spot 1.1.3 (2013-07-09)
59

60
61
62
63
64
65
66
67
  * New feature:
    - The neverclaim parser now understands the new style of output
      used by Spin 6.24 and later.
  * Bug fixes:
    - The scc_filter() function could abort with a BDD error.  If all
      the acceptance sets of an SCC but the first one were useless.
    - The script in bench/spin13/ would not work on MacOS X because
      of some non-portable command.
68
    - A memory corruption in ltlcross.
69

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
70
New in spot 1.1.2 (2013-06-09)
71

72
73
74
75
76
  * Bug fixes:
    - Uninitialized variables in ltlcross (affect the count of terminal
      weak, and strong SCCs).
    - Workaround an old GCC bug to allow compilation with g++ <= 4.5
    - Fix several Doxygen comments so that they display correctly.
77

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
78
New in spot 1.1.1 (2013-05-13):
79

80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
  * New features:

    - lbtt_reachable(), the function that outputs a TGBA in LBTT's
      format, has a new option to indicate that the TGBA being printed
      is in fact a Büchi automaton.  In this case it outputs an LBTT
      automaton with state-based acceptance.

      The output of the guards has also been changed in two ways:
      1. atomic propositions that do not match p[0-9]+ are always
         double-quoted.  This avoids issues where t or f were used as
         atomic propositions in the formula, output as-is in the
         automaton, and read back as true or false.  Other names that
         correspond to LBT operators would cause problem as well.
      2. formulas that label transitions are now output as
         irredundant-sums-of-products.

    - 'ltl2tgba --ba --lbtt' will now output automata with state-based
      acceptance.  You can use 'ltl2tgba --ba --lbtt=t' to force the
      output of transition-based acceptance like in the previous
      versions.

      Some illustrations of this point and the previous one can be
      found in the man page for ltl2tgba(1).

104
105
106
107
108
109
    - There is a new function scc_filter_states() that removes all
      useless states from a TGBA.  It is actually an abbridged version
      of scc_filter() that does not alter the acceptance conditions of
      the automaton.  scc_filter_state() should be used when
      post-processing TGBAs that actually represent BAs.

110
111
112
113
114
115
116
117
118
    - simulation_sba(), cosimulation_sba(), and
      iterated_simulations_sba() are new functions that apply to TGBAs
      that actually represent BAs.  They preserve the imporant
      property that if a state of the BA is is accepting, the outgoing
      transitions of that state are all accepting in the TGBA that
      represent the BA.  This is something that was not preserved by
      functions cosimultion() and iterated_simulations() as mentionned
      in the bug fixes below.

119
120
121
    - ltlcross has a new option --seed, that makes it possible to
      change the seed used by the random graph generator.

122
123
124
125
126
127
128
129
    - ltlcross has a new option --products=N to check the result of
      each translation against N different state spaces, and everage
      the statistics of these N products.  N default to 1; larger
      values increase the chances to detect inconsistencies in the
      translations, and also make the average size of the product
      built against the translated automata a more pertinent
      statistic.

130
131
132
133
    - bdd_dict::unregister_all_typed_variables() is a new function,
      making it easy to unregister all BDD variables of a given type
      owned by some object.

134
  * Bug fixes:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
135
136

    - genltl --gh-r generated the wrong formulas due to a typo.
137
138
    - ltlfilt --eventual and --universal were not handled properly.
    - ltlfilt --stutter-invariant would trigger an assert on PSL formulas.
139
140
    - ltl2tgba, ltl2tgta, ltlcross, and ltlfilt, would all choke on empty
      lines in a file of formulas.  They now ignore empty lines.
141
142
143
144
145
146
147
148
    - The iterated simulation applied on degeneralized TGBA was bogus
      for two reasons: one was that cosimulation was applied using the
      generic cosimulation for TGBA, and the second is that
      SCC-filtering, performed between iterations, was also a
      TGBA-based algorithm.  Both of these algorithms could lose the
      property that if a TGBA represents a BA, all the outgoing
      transitions of a state should be accepting.  As a consequence, some
      formulas where translated to incorrect Büchi automata.
149

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
150
New in spot 1.1 (2013-04-28):
151

152
153
154
155
156
157
158
  Several of the new features described below are discribed in

    Tomáš Babiak, Thomas Badie, Alexandre Duret-Lutz, Mojmír
    Křetínský, Jan Strejček: Compositional Approach to Suspension and
    Other Improvements to LTL Translation.  To appear in the
    proceedings of SPIN'13.

159
  * New features in the library:
160

161
162
163
    - The postprocessor class now takes an optional option_map
      argument that can be used to specify fine-tuning options, making
      it easier to benchmark different scenarios while developing new
164
165
      postprocessings.

166
167
168
169
170
171
    - A new translator class implements a complete translation chain,
      from LTL/PSL to TGBA/BA/Monitor.  It performs pre- and
      post-processings in addition to the core translation, and offers
      an interface similar to that used in the postprocessor class, to
      specify the intent of the translation.

172
173
174
175
    - The degeneralization algorithm has learned three new tricks:
      level reset, level caching, and SCC-based ordering.  The former
      two are enabled by default.  Benchmarking has shown that the
      latter one does not always have a positive effect, so it is
176
      disabled by default.  (See SPIN'13 paper.)
177
178
179
180

    - The scc_filter() function, which removes dead SCCs and also
      simplify acceptance conditions, has learnt how to simplify
      acceptance conditions in a few tricky situations that were not
181
      simplified previously.  (See SPIN'13 paper.)
182

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
183
184
185
186
187
188
189
190
191
    - A new translation, called compsusp(), for "Compositional
      Suspension" is implemented on top of ltl_to_tgba_fm().
      (See SPIN'13 paper.)

    - Some experimental LTL rewriting rules that trie to gather
      suspendable formulas are implemented and can be activated
      with the favor_event_univ option of ltl_simplifier.  As
      always please check doc/tl/tl.tex for the list of rules.

192
193
194
195
196
    - An experimental "don't care" (direct) simulation has been
      implemented.  This simulations consider the acceptance
      of out-of-SCC transitions as "don't care".  It is not
      enabled by default because it currently is very slow.

197
198
199
200
201
202
203
204
205
206
207
    - remove_x() is a function that take a formula, and rewrite it
      without the X operator.  The rewriting is only correct for
      stutter-insensitive LTL formulas (See K. Etessami's paper in IFP
      vol. 75(6). 2000) This algorithm is accessible from the
      command-line using ltlfilt's --remove-x option.

    - is_stutter_insensitive() takes any LTL formula, and check
      whether it is stutter-insensitive.  This algorithm is accessible
      from the command-line using ltlfilt's --stutter-insensitive
      option.

208
209
210
211
212
213
214
215
216
217
218
219
220
    - Several functions have been introduced to check the
      strength of an SCC.
        is_inherently_weak_scc()
	is_weak_scc()
	is_syntactic_weak_scc()
	is_complete_scc()
	is_terminal_scc()
	is_syntactic_terminal_scc()

      Beware that the costly is_weak_scc() function introduced in Spot
      1.0, which is based on a cycle enumeration, has been renammed to
      is_inherently_weak_scc() to match established vocabulary.

221
  * Command-line tools:
222
223

    - ltl2tgba and ltl2tgta now honor a new --extra-options (or -x)
224
225
226
      flag to fine-tune the algorithms used.  The available options
      are documented in the spot-x (7) manpage.  For instance use '-x
      comp-susp' to use the afore-mentioned compositional suspension.
227

228
229
230
231
232
233
    - The output format of 'ltlcross --json' has been changed slightly.
      In a future version we will offer some reporting script that turn
      such JSON output into various tables and graphs, and these change
      are required to make the format usable for other benchmarks (not
      just ltlcross).

234
235
236
237
    - ltlcross will now count the number of non-accepting, terminal,
      weak, and strong SCCs, as well as the number of terminal, weak,
      and strong automata produced by each tool.

238
  * Documentation:
239
240
241
242
243
244

    - org-mode files used to generate the documentation about
      command-line tools (shown at http://spot.lip6.fr/userdoc/tools.html)
      is distributed in doc/org/.  The resulting html files are also
      in doc/userdoc/.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
245
246
247
248
249
250
251
252
253
254
  * Web interface:

    - A new "Compositional Suspension" tab has been added to experiment
      with compositional suspension.

  * Benchmarks:

    - See bench/spin13/README for instructions to reproduce our Spin'13
      benchmark for the compositional suspension.

255
256
  * Bug fixes:

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
257
258
    - There was a memory leak in the LTL simplification code, that could
      only be triggered when disabling advanced simplifications.
259

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
260
261
    - The translation of the PSL formula !{xxx} was incorrect when xxx
      simplified to false.
262

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
263
    - Various warnings triggered by new compilers.
264

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
265
New in spot 1.0.2 (2013-03-06):
266

267
268
269
270
  * New features:
    - the on-line ltl2tgba.html interface can output deterministic or
      non-deterministic monitors.  However, and unlike the ltl2tgba
      command-line tool, it doesn't different output formats.
271
272
273
274
275
276
277
278
279
280
    - the class ltl::ltl_simplifier now has an option to rewrite Boolean
      subformulaes as irredundante-sum-of-product during the simplification
      of any LTL/PSL formula.  The service is also available as a method
      ltl_simplifier::boolean_to_isop() that applies this rewriting
      to a Boolean formula and implements a cache.
      ltlfilt as a new option --boolean-to-isop to try to apply the
      above rewriting from the command-line:
      	    % ltlfilt --boolean-to-isop -f 'GF((a->b)&(b->c))'
	    GF((!a & !b) | (b & c))
      This is currently not used anywhere else in the library.
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
  * Bug fixes:
    - 'ltl2tgba --high' is documented to be the same as 'ltl2tgba',
      but by default ltl2tgba forgot to enable LTL simplifications based
      on language containment, which --high do enable.  There are now
      enabled by default.
    - the on-line ltl2tgba.html interface failed to output monitors,
      testing automata, and generalized testing automata due to two
      issues with the Python bindings.  It also used to display
      Testing Automaton Options when the desired output was set to Monitor.
    - bench/ltl2tgba would not work in a VPATH build.
    - a typo caused some .dir-locals.el configuration parameters to be
      silently ignored by emacs
    - improved Doxygen comments for formula_to_bdd, bdd_to_formula,
      and bdd_dict.
    - src/tgbatest/ltl2tgba (not to be confused with src/bin/ltl2tgba)
      would have a memory leak when passed the conflicting option -M
      and -O.  It probably has many other problems.  Do not use
      src/tgbatest/ltl2tgba if you are not writing a test case for
      Spot.  Use src/bin/ltl2tgba instead.
300

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
301
New in spot 1.0.1 (2013-01-23):
302

303
304
305
306
307
308
309
310
311
  * Bug fixes:
    - Two executions of the simulation reductions could produce
      two isomorphic automata, but with transitions in a different
      order.
    - ltlcross did not diagnose write errors to temporary files,
      and certain versions of g++ would warn about it.
    - "P0.init" is parsed as an atomic even without the double quotes,
      but it was always output with double quotes.  This version will
      not quote this atomic proposition anymore.
312
313
314
315
    - "U", "W", "M", "R" were correctly parsed as atomic propositions
      (instead of binary operators) when placed in double quotes, but
      on output they were output without quotes, making the result
      unparsable.
316
317
    - the to_lbt_string() functions would always output a trailing space.
      This is not the case anymore.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
318
319
    - tgba_product::transition_annotation() would segfault when
      called in a product against a Kripke structure.
320
321
322
323
324
325
  * Minor improvements:
    - Four new LTL simplifications rules:
        GF(a|Xb) = GF(a|b)
        GF(a|Fb) = GF(a|b)
        FG(a&Xb) = FG(a&b)
        FG(a&Gb) = FG(a&b)
326
327
    - The on-line version of ltl2tgba now displays edge and
      transition counts, just as the ltlcross tool.
328
329
    - ltlcross will display the number of timeouts at the end
      of its execution.
330
331
    - ltlcross will diagnose tools with missing input or
      output %-sequence before attempting to run any of them.
332
333
334
335
    - The parser for LBT's prefix-style LTL formulas will now
      read atomic propositions that are not of the form p1, p2...
      This makes it possible to process formulas written in
      ltl2dstar's syntax.
336
337
338
339
340
341
342
343
344
345
346
347
348
  * Pruning:
    - lbtt has been removed from the distribution.  A copy of the last
      version we distributed is still available at
        http://spot.lip6.fr/dl/lbtt-1.2.1a.tar.gz
      and our test suite will use it if it is installed, but the same
      tests are already performed by ltlcross.
    - the bench/ltl2tgba/ benchmark, that used lbtt to compare various
      LTL-to-Büchi translators, has been updated to use ltlcross.  It
      now output summary tables in LaTeX.  Support for Modella (no
      longer available online), and Wring (requires a too old Perl
      version) have been dropped.
    - the half-baked and underdocumented "Event TGBA" support in
      src/evtgba*/ has been removed, as it was last worked on in 2004.
349

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
350
New in spot 1.0 (2012-10-27):
351

352
353
354
355
  * License change: Spot is now distributed using GPL v3+ instead
    of GPL v2+.  This is because we started using some third-party
    files distributed under GPL v3+.

356
357
358
359
  * Command-line tools

    Useful command-line tools are now installed in addition to the
    library.  Some of these tools were originally written for our test
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
360
    suite and had evolved organically into useful programs with crappy
361
362
363
    interfaces: they have now been rewritten with better argument
    parsing, saner defaults, and they come with man pages.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
364
    - genltl:   Generate LTL formulas from scalable patterns.
365
366
367
368
369
370
                This offers 20 patterns so far.

    - randltl:  Generate random LTL/PSL formulas.

    - ltlfilt:  Filter lists of formulas according to several criteria
                (e.g., match only safety formulas that are larger than
371
372
373
374
375
		some given size).  Besides being used as a "grep" tool
		for formulas, this can also be used to convert
		files of formulas between different syntaxes, apply
		some simplifications, check whether to formulas are
		equivalent, ...
376

377
    - ltl2tgba: Translate LTL/PSL formulas into Büchi automata (TGBA,
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
378
                BA, or Monitor).  A fundamental change to the
379
380
381
                interface is that you may now specify the goal of the
                translation: do you you favor deterministic or smaller
                automata?
382
383
384

    - ltl2tgta: Translate LTL/PSL formulas into Testing Automata.

385
    - ltlcross: Compare the output of translators from LTL/PSL to
386
387
388
389
                Büchi automata, to find bug or for benchmarking.  This
                is essentially a Spot-based reimplementation of LBTT
                that supports PSL in addition to LTL, and that can
                output more statistics.
390

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
391
392
393
394
395
    An introduction to these tools can be found on-line at
      http://spot.lip6.fr/userdoc/tools.html

    The former test versions of genltl and randltl have been removed
    from the source tree.  The old version of ltl2tgba with its
396
    gazillion options is still in src/tgbatest/ and is meant to be
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
397
398
399
    used for testing only.  Although ltlcross is meant to replace
    LBTT, we are still using both tools in this release; however this
    is likely to be the last release of Spot that redistributes LBTT.
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429

  * New features in the Spot library:

    - Support for various flavors of Testing Automata.

      The flavors are:
      + "classical" Testing Automata, as used for instance by
	Geldenhuys and Hansen (Spin'06), using Büchi and
	livelock acceptance conditions.
      + Generalized Testing Automata, extending the previous
	with multiple Büchi acceptance sets.
      + Transition-based Generalized Testing Automata moving Büchi
        acceptance to transitions, and getting rid of livelock
        acceptance conditions by expliciting stuttering self-loops.

      Supporting algorithms include anything required to run
      the automata-theoretic approach using testing automata:

      + dedicated synchronized product
      + dedicated emptiness-check for TA and GTA, as these
        may require two passes because of the two kinds of
	acceptance, while a TGTA can be checked for emptiness
	with the same one-pass algorithm as a TGBA.
      + conversion from a TGBA to any of the above kind, with
        options to reduce these automata with bisimulation,
	and to produce a BA/GBA that require a single pass
	(at the expense of determinism).
      + output in dot format for display

      A discussion of these automata, part of Ala Eddine BEN SALEM's
430
      PhD work, should appear in ToPNoC VI (LNCS 7400).  The web-based
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
431
      interface and the aforementioned ltl2tgta tool can be used
432
      to build testing automata.
433
434
435
436
437
438
439

    - TGBA can now be reduced by Reverse Simulation (in addition to
      the Direct Simulation introduced in 0.9).  A function called
      iterated_simulations() will alternate direct and reverse
      simulations in a loop as long as it diminishes the size of the
      automaton.

440
    - The enumerate_cycles class implements the Loizou-Thanisch
441
442
443
444
      algorithm to enumerate elementary cycles in a SCC.  As an
      example of use, is_weak_scc() will tell whether an SCC is
      inherently weak (all its cycles are accepting, or none of them
      are).
445
446
447
448
449
450

    - parse_lbt() will parse an LTL formula expressed in the prefix
      syntax used (at least) by LBT, LBTT and Scheck.
      to_lbt_string() can be used to print an LTL formula using this
      syntax.

451
452
453
    - to_wring_string() can be used to print an LTL formula into
      Wring's syntax.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
454
    - The LTL/PSL parser now has a lenient mode that can be useful
455
456
457
458
459
460
461
      to interpret atomic proposition with language-specific constructs.
      In lenient mode, any (...) or {...} block that cannot be parsed
      as formula will be assumed to be an atomic proposition.
      For instance the input (a < b) U (process[2]@ok), normally
      flagged as a syntax error, is read as "a < b" U "process[2]@ok"
      in lenient mode.

462
463
464
    - minimize_obligation() has a new option to disable WDBA
      minimization it cases it would produce a deterministic automaton
      that is bigger than the original TGBA.  This can help
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
465
      choosing between less states or more determinism.
466
467
468
469
470
471

    - new functions is_deterministic() and count_nondet_states()
      (The count of nondeterministic states is now displayed on
      automata generated with the web interface.)

    - A new class, "postprocessor", makes it easier to apply
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
472
      all available simplification algorithms on a TGBA/BA/Monitors.
473
474
475
476
477
478
479
480

  * Minor changes:

    - The '*' operator can (again) be used as an AND in LTL formulas.
      This is for compatibility with formula written in Wring's
      syntax.  However inside SERE it is interpreted as the Kleen
      star.

481
482
483
484
485
486
487
    - When printing a formula using Spin's LTL syntax, we don't
      double-quote complex atomic propositions (that was not valid
      Spin input anyway).   For instance F"foo == 2" used to be
      output as <>"foo == 2".  We now output <>(foo == 2) instead.
      The latter syntax is understood by Spin 6.  It can be read
      back by Spot in lenient mode (see above).

488
489
490
    - The gspn-ssp benchmark has been removed.


Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
491
New in spot 0.9.2 (2012-07-02):
492

493
494
495
  * New features to the web interface.
    - It can run ltl3ba (Babiak et al., TACAS'12) where available.
    - "a loading logo" is displayed when result is not instantaneous.
496
497
498
499
500
  * Speed improvements:
    - The unicity hash table of BuDDy has been separated separated
      node table for better cache-friendliness.  The resulting speedup
      is around 5% on BDD-intensive algorithms.
    - A new BDD operation, called bdd_implies() has been added to
501
      BuDDy to check whether one BDD implies another.  This benefits
502
      mostly the simulation and degeneralization algorithms of Spot.
503
504
505
    - A new offline implementation of the degeneralization (which
      had always been performed on-the-fly so far) available.  This
      especially helps the Safra complementation.
506
507
508
  * Bug fixes:
    - The CGI script running for ltl2tgba.html will correctly timeout
      after 30s when Spot's translation takes more time.
509
510
511
512
513
514
    - Applying WDBA-minimization on an automaton generated by the
      Couvreur/LaCIM translator could lead to an incorrect automaton
      due to a bug in the definition of product with symbolic
      automata.
    - The Makefile.am of BuDDy, LBTT, and Spot have been adjusted to
      accomodate Automake 1.12 (while still working with 1.11).
515
    - Better error recovery when parsing broken LTL formulae.
516
517
    - Fix errors and warnings reported by clang 3.1 and the
      upcoming g++ 4.8.
518

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
519
New in spot 0.9.1 (2012-05-23):
520

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
521
  * The version of LBTT we distribute includes a patch from Tomáš
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
    Babiak to count the number of non-deterministic states, and the
    number of deterministic automata produced.
    See lbtt/NEWS for the list of other differences with the original
    version of LBTT 1.2.1.
  * The Couvreur/FM translator has learned two new tricks.  These only
    help to speedup the translation by not issuing states or
    acceptance conditions that would be latter suppresed by other
    optimizations.
    - The translation rules used to translate subformulae of the G
      operator have been adjusted not to produce useless loops
      already implied by G.  This generalizes the "GF" trick
      presented in Couvreur's original FM'99 paper.
    - Promises generated for formula of the form P(a U (b U c))
      are reduced into P(c), avoiding the introduction of many
      promises that imply each other.
537
538
  * The tgba_parse() function is now available via the Python
    bindings.
539
540
541
  * Bug fixes:
    - The random SERE generator was using the wrong operators
      for "and" and "or", mistaking And/Or with AndRat/OrRat.
542
543
    - The translation of !{r} was incorrect when this subformula
      was recurring (e.g. in G!{r}) and r had loops.
544
    - Correctly recognize ltl2tgba's option -rL.
545
546
547
548
549
550
551
    - Using LTL simplification rules based on syntactic implication,
      or based on language containment checks, caused BDD variables
      to be allocated in an "unnatural" order, resulting in a slower
      translation and a less optimal degeneralization.
    - When ltl2tgba reads a neverclaim, it now considers the resulting
      TGBA as a Büchi automaton, and will display double circles in
      the dotty output.
552

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
553
New in spot 0.9 (2012-05-09):
554

555
  * New features:
556
557
558
559
560
561
562
563
564
    - Operators from the linear fragment of PSL are supported.  This
      basically extends LTL with Sequential Extended Regulat
      Expressions (SERE), and a couple of operators to bridge SERE and
      LTL.  See doc/tl/tl.pdf for the list of operators and their
      semantics.
    - Formula rewritings have been completely revamped, and augmented
      with rules for PSL operators (and some new LTL rules as well).
      See doc/tl/tl.pdf for the list of the rewritings implemented.
    - Some of these rewritings that may produce larger formulas
565
      (for instance to rewrite "{a;b;c}" into "a & X(b & Xc)")
566
567
568
569
570
571
572
573
      may be explicitely disabled with a new option.
    - The src/ltltest/randltl tool can now generate random SEREs
      and random PSL formulae.
    - Only one translator (ltl2tgba_fm) has been augmented to
      translate the new SERE and PSL operators.  The internal
      translation from SERE to DFA is likely to be rewriten in a
      future version.
    - A new function, length_boolone(), computes the size of an
574
575
576
577
578
579
580
      LTL/PSL formula while considering that any Boolean term has
      length 1.
    - The LTL/PSL parser recognizes some UTF-8 characters (like ◇ or
      ∧) as operators, and some output routines now have an UTF-8
      output mode.  Tools like randltl and ltl2tgba have gained an -8
      option to enable such output.  See doc/tl/tl.pdf for the list
      of recognized codepoints.
581
    - A new direct simulation reduction has been implemented.  It
582
      works directly on TGBAs.  It is in src/tgbaalgos/simlation.hh,
583
      and it can be tested via ltl2tgba's -RDS option.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
584
    - unabbreviate_wm() is a function that rewrites the W and M operators
585
586
587
588
589
      of LTL formulae using R and U.  This is called whenever we output
      a formula in Spin syntax.  By combining this with the aforementioned
      PSL rewriting rules, many PSL formulae that use simple SERE can be
      converted into LTL formulae that can be feed to tools that only
      understand U and R.  The web interface will let you do this.
590
591
592
    - changes to the on-line translator:
      + SVG output is available
      + can display some properties of a formula
593
594
      + new options for direct simulation, larger rewritings, and
        utf-8 output
595
596
597
598
    - configure --without-included-lbtt will prevent LBTT from being
      configured and built.  This helps on systems (such as MinGW)
      where LBTT cannot be built.  The test-suite will skip any
      LBTT-based test if LBTT is missing.
599
  * Interface changes:
600
    - Operators ->, <->, U, W, R, and M are now parsed as
601
      right-associative to better match the PSL standard.
602
603
604
605
606
607
608
609
610
611
612
613
614
615
    - The constructors for temporal formulae will perform some trivial
      simplifications based on associativity, commutativity,
      idempotence, and neutral elements.  See doc/tl/tl.pdf for the
      list of such simplifications.
    - Formula instances now have many methods to inspect their
      properties (membership to syntactic classes, absence of X
      operator, etc...) in constant time.
    - LTL/PSL formulae are now handled everywhere as 'const formula*'
      and not just 'formula*'.  This reflects the true nature of these
      (immutable) formula objects, and cleanups a lot of code.
      Unfortunately, it is a backward incompatible change: you may have
      to add 'const' to a couple of lines in your code, and change
      'ltl::const_vistitor' into 'ltl::visitor' if you have written a
      custom visitor.
616
617
618
619
    - The new entry point for LTL/PSL simplifications is the function
      ltl_simplifier::simplify() declared in src/ltlvisit/simplify.hh.
      The ltl_simplifier class implements a cache.
      Functions such as reduce() or reduce_tau03() are deprecated.
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
    - The old game-theory-based implementations for direct and delayed
      simulation reductions have been removed.  The old direct
      simulation would only work on degeneralized automata, and yet
      produce results inferior to the new direct simulation introduced
      in this release.  The implementation of delayed simulation was
      unreliable.  The function reduc_tgba_sim() has been kept
      for compatibility (it calls the new direct simulation whatever
      the type of simulation requested) and marked as deprecated.
      ltl2tgba's options -Rd, -RD are gone.  Options -R1t, -R1s,
      -R2s, and -R2t are deprecated and all made equivalent to -RDS.
    - The tgba_explicit hierarchy has been reorganized in order to
      make room for sba_explicit classes that share most of the code.
      The main consequence is that the tgba_explicit type no longuer
      exists.  However the tgba_explicit_number,
      tgba_explicit_formula, and tgba_explicit_string still do.
635

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
636
New in spot 0.8.3 (2012-03-09):
637

638
639
  * Support for both Python 2.x and Python 3.x.
    (Previous versions would only work with Python 2.x.)
640
641
  * The online ltl2tgba.html now stores its state in the URL so that
    history is preserved, and links to particular setups can be sent.
642
643
644
645
  * Bug fixes:
    - Fix a segfault in the compression code used by the -Z
      option of dve2check.
    - Fix a race condition in the CGI script.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
646
    - Fix a segfault in the CGI script when computing a Büchi run.
647

648
New in spot 0.8.2 (2012-01-19):
649

650
651
  * configure now has a --disable-python option to disable
    the compilation of Python bindings.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
652
  * Minor speedups in the Safra complementation.
653
  * Better memory management for the on-the-fly degeneralization
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
654
    algorithm.  This mostly benefits to the Safra complementation.
655
656
657
  * Bug fixes:
    - spot::ltl::length() forgot to count the '&' and '|' operators
      in an LTL formula.
658
659
    - minimize_wdba() could fail to mark some transiant SCCs as accepting,
      producing an automaton that was not fully minimized.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
660
    - minimize_dfa() could produce incorrect automata, but it is not
661
662
663
      clear whether this could have had an inpact on WDBA minimization
      (the worse case is that some TGBA would not have been minimized
      when they could).
664
    - Fix a Python syntax error in the CGI script.
665
666
    - Fix compilation with g++ 4.0.
    - Fix a make check failure when valgrind is missing.
667

668
New in spot 0.8.1 (2011-12-18):
669

670
671
672
673
674
675
676
677
  * Only bug fixes:
    - When ltl2tgba is set to perform both WDBA minimization and
      degeneralization, do the latter only if the former failed.
      In previous version, automata were (uselessly) degeneralized
      before WDBA minimization, causing important slowdowns.
    - Fix compilation with Clang 3.0.
    - Fix a Makefile setup causing a "make check" failure on MacOS X.
    - Fix an mkdir error in the CGI script.
678

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
679
New in spot 0.8 (2011-11-28):
680

681
682
  * Major new features:
    - Spot can read DiVinE models.  See iface/dve2/README for details.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
683
    - The genltl tool can now output 20 different LTL formula families.
684
      It also replaces the LTLcounter Perl scripts.
685
    - There is a printer and parser for Kripke structures in text format.
686
687
688
689
690
  * Major interface changes:
    - The destructor of all states is now private.  Any code that looks like
      "delete some_state;" will cause an compile error and should be
      updated to "some_state->destroy();".  This new syntax is supported
      since version 0.7.
691
    - The experimental Nips interface has been removed.
692
693
694
695
696
697
  * Minor changes:
    - The dotty_reachable() function has a new option "assume_sba" that
      can be used for rendering automata with state-based acceptance.
      In that case, acceptance states are displayed with a double
      circle. ltl2tgba (both command line and on-line) Use it to display
      degeneralized automata.
698
699
700
    - The dotty_reachable() function will also display transition
      annotations (as returned by the tgba::transitition_annotation()).
      This can be useful when displaying (small) state spaces.
701
702
703
    - Identifiers used to name atomic proposition can contain dots.
      E.g.: X.Y is now an atomic proposition, while it was understood
      as X&Y in previous versions.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
704
    - The Doxygen documentation is no longer built as a PDF file.
705
706
707
  * Internal improvements:
    - The on-line ltl2tgba CGI script uses a cache to produce faster
      answers.
708
709
710
    - Better memory management for the states of explicit automata.
      Thanks to the aforementioned ->destroy() change, we can avoid
      cloning explicit states.
711
712
713
714
    - tgba_product has learned how to be faster when one of the operands
      is a Kripke structure (15% speedup).
    - The reduction rule for "a M b" has been improved: it can be
      reduced to "a & b" if "a" is a pure eventuallity.
715
716
717
718
719
    - More useless acceptance conditions are removed by SCC simplifications.
  * Bug fixes:
    - Safra complementation has been fixed in cases where more than
      one acceptance conditions where needed to convert the
      deterministic Streett automaton as a TGBA.
720
    - The degeneralization is now idempotent.  Previously, degeneralizing
721
722
723
724
      an already degeneralized automaton could add some states.
    - The degeneralization now has a deterministic behavior.  Previously
      it was possible to obtain different output depending on the
      memory layout.
725
726
727
728
729
730
731
732
    - Spot now outputs neverclaims with fully parenthesized guards.
      I.e., instead of
         (!x && y) -> goto S1
      it now outputs
         ((!(x)) && (y)) -> goto S1
      This prevents problems when the model defines `x' as
         #define x flag==0
      because !x then evaluated to (!flag)==0 instead of !(flag==0).
733

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
734
New in spot 0.7.1 (2011-02-07):
735

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
736
737
738
739
740
741
  * The LTL parser will accept operator ~ (for not) as well
    as --> and <--> (for implication and equivalence), allowing
    formulae from the Büchi Store to be read directly.
  * The neverclaim parser will accept guards of the form
        :: !(...) -> goto ...
    instead of the more commonly used
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
742
        :: (!(...)) -> goto ...
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
743
744
    This makes it possible to read neverclaims provided by the Büchi Store.
  * A new ltl2tgba option, -kt, will count the number of "sub-transitions".
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
745
    I.e., a transition labelled by "true" counts for 4 "sub-transitions"
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
746
747
748
    if the automaton uses 2 atomic propositions.
  * Bugs fixed:
    - Fix segfault during WDBA minimization on automata with useless states.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
749
    - Use the included BuDDy library if the one already installed
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
750
751
      is older than the one distributed with Spot 0.7.
    - Fix two typos in the code of the CGI scripts.
752

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
753
New in spot 0.7 (2011-02-01):
754

755
756
757
758
759
  * Spot is now able to read an automaton expressed as a Spin neverclaim.
  * The "experimental" Kripke structure introduced in Spot 0.5 has
    been rewritten, and is no longer experimental.  We have a
    developement version of checkpn using it, and it should be
    released shortly after Spot 0.7.
760
761
762
  * The function to_spin_string(), that outputs an LTL formula using
    Spin's syntax, now takes an optional argument to request
    parentheses at all levels.
763
764
  * src/ltltest/genltl is a new tool that generates some interesting
    families of LTL formulae, for testing purpose.
765
  * bench/ltlclasses/ uses the above tool to conduct the same benchmark
766
    as in the DepCoS'09 paper by Cichoń et al.  The resulting benchmark
767
768
    completes in 12min, while it tooks days (or exhausted the memory)
    when the paper was written (they used Spot 0.4).
769
  * Degeneralization has again been improved in two ways:
770
    - It will merge degeneralized transitions that can be merged.
771
    - It uses a cache to speed up the improvement introduced in 0.6.
772
773
  * An implementation of Dax et al.'s paper for minimizing obligation
    formulae has been integrated.  Use ltl2tgba -Rm to enable this
774
775
    optimization from the command-line; it will have no effect if the
    property is not an obligation.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
776
777
  * bench/wdba/ conducts a benchmark similar to the one on Dax's
    webpage, comparing the size of the automata expressing obligation
778
779
    formula before and after minimization.  See bench/wdba/README for
    results.
780
  * Using similar code, Spot can now construct deterministic monitors.
781
782
783
784
  * New ltl2tgba options:
    -XN: read an input automaton as a neverclaim.
    -C, -CR: Compute (and display) a counterexample after running the
             emptiness check.  With -CR, the counterexample will be
785
786
             replayed on the automaton to ensure it is correct
	     (previous version would always compute a replay a
787
788
	     counterexample when emptiness-check was enabled)
    -ks: traverse the automaton to compute its number of states and
789
         transitions (this is faster than -k which will also count
790
         SCCs and paths).
791
    -M: Build a deterministic monitor.
792
793
794
    -O: Tell whether a formula represents a safety, guarantee, or
        obligation property.
    -Rm: Minimize automata representing obligation properties.
795
796
797
  * The on-line tool to translate LTL formulae into automata
    has been rewritten and is now at http://spot.lip6.fr/ltl2tgba.html
    It requires a javascript-enabled browser.
798
799
800
801
802
  * Bug fixes:
    - Location of the errors messages in the TGBA parser where inaccurate.
    - Various warning fixes for different versions of GCC and Clang.
    - The neverclaim output with ltl2tgba -N or -NN used to ignore any
      automaton simplification performed after degeneralization.
803
    - The formula simplification based on universality and eventuality
804
      had a quadratic run-time.
805

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
806
New in spot 0.6 (2010-04-16):
807

808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
  * Several optimizations to improve some auxiliary steps
    of the LTL translation (not the core of the translation):
    - Better degeneralization
    - SCC simplifications has been tuned for degeneralization
      (ltl2tgba now has two options -R3 and -R3f: the latter will
      remove every acceptance condition that used to be removed
      in Spot 0.5 while the former will leave useless acceptance conditions
      going to accepting SCC.  Experience shows that -R3 is more
      favorable to degeneralization).
    - ltl2tgba will perform SCC optimizations before degeneralization
      and not the converse
    - We added a syntactic simplification rule to rewrite F(a)|F(b) as F(a|b).
      We only had a rule for the more specific FG(a)|FG(b) = F(Ga|Gb).
    - The syntactic simplification rule for F(a&GF(b)) = F(a)&GF(b) has
      be disabled because the latter formula is in fact harder to translate
      efficiently.
824
825
826
827
828
829
830
831
832
833
834
835
  * New LTL operators: W (weak until) and its dual M (strong release)
    - Weak until allows many LTL specification to be specified more
      compactly.
    - All LTL translation algorithms have been updated to
      support these operators.
    - Although they do not add any expressive power, translating
      "a W b" is more efficient (read smaller output automaton) than
      translating the equivalent form using the U operator.
    - Basic syntactic rewriting rules will automatically rewrite "a U
      (b | G(a))" and "(a U b)|G(a)" as "a W b", so you will benefit
      from the new operators even if you do not use them.  Similar
      rewriting rules exist for R and M, although they are less used.
836
837
838
839
840
841
842
  * New options have been added to the CGI script for
    - SVG output
    - SCC simplifications
  * Bug fixes:
    - The precedence of the "->" and "<->" Boolean operators has been
      adjusted to better match other tools.
      Spot <= 0.5 used to parse "a & b -> c & d" as "a & (b -> c) & d";
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
843
      Spot >= 0.6 will parse it as "(a & b) -> (c & d)".
844
845
846
    - The random graph generator was fixed (again!) not to produce
      dead states as documented.
    - Locations in the error messages of the LTL parser were off by one.
847

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
848
New in spot 0.5 (2010-02-01):
849
850
851
852
853

  * We have setup two mailing lists:
    - <spot-announce@lrde.epita.fr> is read-only and will be used to
      announce new releases.  You may subscribe at
      https://www.lrde.epita.fr/mailman/listinfo/spot-announce
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
854
    - <spot@lrde.epita.fr> can be used to discuss anything related
855
856
857
      to Spot.  You may subscribe at
      https://www.lrde.epita.fr/mailman/listinfo/spot-announce
  * Two new LTL translations have been implemented:
858
859
860
861
862
    - eltl_to_tgba_lacim() is a symbolic translation for ELTL based on
      Couvreur's LaCIM'00 paper.  For this translation (available with
      ltl2tgba's option -le), all operators are described as finite
      automata.  A default set of operators is provided for LTL
      (option -lo) and user may add more automaton operators.
863
864
    - ltl_to_taa() is a translation based on Tauriainen's PhD thesis.
      LTL is translated to "self-loop" alternating automata
865
866
      and then to Transition-based Generalized Automata.  (ltl2tgba's
      option -taa).
867
868
869
870
871
    The "Couvreur/FM" translation remains the best LTL translation
    available in Spot.
  * The data structures used to represent LTL formulae have been
    overhauled, and it resulted in a big performence improvement
    (in time and memory consumption) for the LTL translation.
872
  * Two complementation algorithms for state-based Büchi automata
873
    have been implemented:
874
    - tgba_kv_complement is an on-the-fly implementation of the
875
876
877
      Kupferman-Vardi construction (TCS'05) for generalized acceptance
      conditions.
    - tgba_safra_complement is an implementation of Safra's
878
879
      complementation.  This algorithm takes a degeneralized Büchi
      automaton as input, but our implementation for the Streett->Büchi
880
881
882
      step will produce a generalized automaton in the end.
  * ltl2tgba has gained several options and the help text has been
    reorganized.  Please run src/tgbatest/ltl2tgba without arguments
883
    for details.  Couvreur/FM is now the default translation.
884
  * The ltl2tgba.py CGI script can now run standalone.  It also offers
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
885
886
    the Tauriainen/TAA translation, and some options for SCC-based
    reductions.
887
888
889
890
891
  * Automata using BDD-encoded transitions relation can now be pruned
    for useless states symbolically using the delete_unaccepting_scc()
    function.  This is ltl2tgba's -R3b option.
  * The SCC-based simplification (ltl2tgba's -R3 option) has been
    rewritten and improved.
892
893
894
  * The "*" symbol, previously parsed as a synonym for "&" is no
    longer recognized.  This makes room for an upcoming support of
    rational operators.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
895
  * More benchmarks in the bench/ directory:
896
897
898
899
900
901
902
    - gspn-ssp/    some benchmarks published at ACSD'07,
    - ltlcounter/  translation of a class of LTL formulae used by
                     Rozier & Vardi at SPIN'07
    - scc-stats/   SCC statistics after translation of LTL formulae
    - split-product/ parallelizing gain after splitting LTL automata
  * An experimental Kripke interface has been developed to simplify
    the integration of third party tools that do not use acceptance
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
903
    conditions and that have label on states instead of transitions.
904
    This interface has not been used yet.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
905
  * Experimental interface with the Nips virtual machine.
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
    It is not very useful as Spot isn't able to retrieve any property
    information from the model.  This will just check assertions.
  * Distribution:
    - The Boost C++ library is now required.
    - Update to Autoconf 2.65, Automake 1.11.1, Libtool 2.2.6b,
      Bison 2.4.1, and Swig 1.3.40.
    - Thanks to the newest Automake, "make check" will now
      run in parallel if you use "make -j2 check" or more.
  * Bug fixes:
    - Disable warnings from the garbage collection of BuDDy, it
      could break the standard output of ltl2tgba.
    - Fix several C++ constructs to ensure Spot will build with
      GCC 4.3, 4.4, and older 3.x releases, as well as with Intel's
      ICC compiler.
    - A very old bug in the hash function for LTL formulae caused Spot
      to sometimes (but very rarely) consider two different LTL formulae
      as equal.
923

924
New in spot 0.4 (2007-07-17):
925

926
927
928
929
930
931
932
933
934
935
936
  * Upgrade to Autoconf 2.61, Automake 1.10, Bison 2.3, and Swig 1.3.31.
  * Better LTL simplifications.
  * Don't initialize Buddy if it has already been initialized (in case
    the client software is already using Buddy).
  * Lots of work in the greatspn interface for our ACSD'05 paper.
  * Bug fixes:
    - Fix the random graph generator not to produce dead states as documented.
    - Fix synchronized product in case both side use acceptance conditions.
    - Fix some syntax errors with newer versions of GCC.

New in spot 0.3 (2006-01-25):
937
938
939
940
941
942
943

  * lbtt 1.2.0
  * The CGI script for LTL translation also offers emptiness check algorithms.
  * tau03_opt_search implements the "ordering heuristic".
    (Submitted by Heikki Tauriainen.)
  * A couple of bugs were fixed into the LTL or automata simplifications.

944
945
946
947
948
949
950
951
952
953
954
955
New in spot 0.2 (2005-04-08):

  * Emptiness checks:
    - the new spot::option_map class is used to pass options to
      emptiness-check algorithms.
    - the new emptiness_check_instantiator class is used to turn a
      string such as `algorithm(option1, option2)' into an actual
      instance of this emptiness-check algorithm with the given
      options.  All tools use this.
    - tau03_opt_search implements the "condition heuristic".
      (Suggested by Heikki Tauriainen.)
  * Minor bug fixes.
956

957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
New in spot 0.1 (2005-01-31):

  * Emptiness checks:
    - They all follow the same interface, and gather statistical data.
    - New algorithms: gv04.hh, se05.hh, tau03.hh, tau03opt.hh
    - New options for couvreur99: poprem and group.
    - reduce_run() try to reduce accepting runs produced by emptiness checks.
    - replay_run() ensure accepting runs are actually accepting runs.
  * New testing tools:
    - ltltest/randltl: Generate random LTL formulae.
    - tgbatest/randtgba: Generate random TGBAs.  Optionally multiply them
        against random LTL formulae.  Optionally check them for emptiness
        with all available algorithms.  Optionally gather statistics.
  * bench/emptchk/: Contains scripts that benchmark emptiness-checks.
  * Split the degeneralization proxy in two:
    - tgba_tba_proxy  uses at most max(N,1) copies
    - tgba_sba_proxy  uses at most 1+max(N,1) copies and has a
                      state_is_accepting() method
  * tgba::transition_annotation annotate a transition with some string.
    This comes handy to associate that transition to its high-level name.
  * Preliminary support for Event-based GBA (the evtgba*/ directories).
    This might as well disappear in a future release.
  * LTL formulae are now sorting using their string representation, instead
    of their memory address (which is still unique).  This makes the output
    of the various functions more deterministic.
  * The Doxygen documentation is now organized using modules.
983

984
985
986
987
988
989
990
991
992
New in spot 0.0x (2004-08-13):

  * New atomic_prop_collect() function: collect atomic propositions
    in an LTL formula.
  * Fix several typos in documentation, and some warnings in the code.
  * Now compiles on Darwin and Cygwin.
  * Upgrade to Automake 1.9.1, and lbtt 1.1.2.
    (And drop support for older lbtt versions.)
  * Support newer versions of Valgrind (>= 2.1.0).
993

994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
New in spot 0.0v (2004-06-29):

  * LTL formula simplifications using basic rewriting rules,
    a-la Wring syntactic approximations, and Etessami's universal
    and existential classes.
     - Function reduce() in ltlvisit/reduce.hh is the main interface.
     - Can be tested with the CGI script.
  * TGBA simplifications using direct simulation, delayed simulation,
    and SCC-based simplifications.  This is still experimental.
  * The LTL parser will now read LTL formulae written using Wring's syntax.
  * ltl2tgba_fm() now has options for on-the-fly fair-loop approximations,
    and Modella-like branching-postponement.
  * GreatSPN interface:
     - The `declarative_environment' is now part of Spot itself rather than
       part of the interface with GreatSPN.
     - the RG and SRG interface can deal with dead markings in three
       ways (omit deadlocks from the state graph, stutter on the deadlock
       and consider as a regular behavior, or stutter and distinguish the
       deadlock with a property).
     - update SSP interface to Soheib Baarir latest work.
  * Preliminary Python bindings for BuDDy's FDD and BVEC.
  * Upgrade to BuDDy 2.3.
1016

1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
New in spot 0.0t (2004-04-23):

  * `emptiness_check':
      - fix two bugs in the computation of the counter example,
      - revamp the interface for better customization.
  * `never_claim_reachable': new function.
  * Introduce annonymous BDD variables in `bdd_dict', and start
    to use it in `ltl_to_tgba_fm'.
  * Offer never claim in the CGI script.
  * Rename EESRG as SSP, and offer specialized variants of the
    emptiness_check.
1028

1029
1030
1031
1032
1033
1034
1035
1036
1037
New in spot 0.0r (2004-03-08):

  * In ltl_to_tgba_fm:
    - New option `exprop' to optimize determinism.
    - Make the `symbolic indentification' from 0.0p optional.
  * `nonacceptant_lbtt_reachable' new function to help getting
    accurate statistics from LBTT.
  * Revamp the cgi script's user interface.
  * Upgrade to lbtt 1.0.3, swig 1.3.21, automake 1.8.3
1038

1039
1040
1041
1042
1043
1044
1045
1046
New in spot 0.0p (2004-02-03):

  * In ltl_to_tgba_fm:
    - identify states with identical symbolic expansions
      (i.e., identical continuations)
    - use Acc[b] as acceptance condition for Fb, not Acc[Fb].
  * Update and speed-up the cgi script.
  * Improve degeneralization.
1047

1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
New in spot 0.0n (2004-01-13):

  * emptiness_check::check2() is a variant of Couvreur's emptiness check that
    explores visited states first.
  * Build the EESRG supporting code condinally, as the associated
    GreatSPN changes have not yet been contributed to GreatSPN.
  * Add a powerset algorithm (determinize TGBA ignoring acceptance
    conditions, i.e., as if they were used to recognize finite languages).
  * tgba_explicit::merge_transitions: merge transitions with same source,
    destination, and acceptance condition.
  * Run test cases within valgrind.
  * Various bug fixes.
1060

1061
New in spot 0.0l (2003-12-01):
1062
1063
1064
1065
1066
1067
1068
1069

  * Computation of prime implicants.  This simplify the output of
    ltl_to_tgba_fm, and allows conditions to be output as some of
    product in dot output.
  * Optimize translation of GFy in ltl_to_tgba_fm.
  * tgba_explicit supports arbitrary binary formulae on transitions
    (only conjunctions were allowed).

1070
New in spot 0.0j (2003-11-03):
1071
1072
1073
1074
1075
1076
1077
1078

  * Use hash_map's instead of map's almost everywhere.
  * New emptiness check, based on Couvreur's algorithm.
  * LTL propositions can be put inside doublequotes to disambiguate
    some constructions.
  * Preliminary support for GreatSPN's EESRG.
  * Various bug fixes.

1079
1080
1081
1082
1083
New in spot 0.0h (2003-08-18):

  * More python bindings:
    - "import buddy" works (see wrap/python/tests/bddnqueen.py for an example),
    - almost all the Spot API is now available via "import spot".
1084
  * wrap/python/cgi/ltl2tgba.py is an LTL-to-Büchi translator that
1085
1086
1087
    work as as a cgi script.
  * Couvreur's FM'99 ltl-to-tgba translation.

1088
1089
1090
1091
1092
1093
1094
New in spot 0.0f (2003-08-01):

  * More python bindings, still only for the spot::ltl:: namespace.
  * Functional GSPN interface.  (Enable with --with-gspn=directory.)
  * The LTL scanner recognizes /\, \/, and xor.
  * Upgrade to lbtt 1.0.2.
  * tgba_tba_proxy is an on-the-fly degeneralizer.
1095
  * Implements the "magic search" algorithm.
1096
1097
1098
1099
1100
1101
1102
    (Works only on a tgba_tba_proxy.)
  * Tgba's output algorithms (save(), dotty()) now non-recursive.
  * During products, succ_iter will optimize its set of successors
    using information computed from the current product state.
  * BDD dictionnaries are now shared between automata and.  This
    gets rid of all the BDD-variable translating machinery.

1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
New in spot 0.0d (2003-07-13):

  * Optimize translation of G operators occurring at the root
    of a formula (or its immediate children when the root is a
    conjunction).  This saves two BDD variables per G operator.
  * Distribute lbtt, and run it during `make check'.
  * First sketch of GSPN interface.
  * succ_iter_concreate::next() completely rewritten.
  * Transitions are now labelled by boolean formulae (not only
    conjunctions).
  * Documentation:
    - Output collaboration diagrams.
    - Build and distribute PDF manual.
  * Many bug fixes.

New in spot 0.0b (2003-06-26):

  * Everything.