NEWS 67.3 KB
Newer Older
1
2
New in spot 1.2.4a (not yet released)

3
  * New features:
4
5
6

    - The online ltl2tgba translator will automatically attempt to
      parse a formula using LBT's syntax if it cannot parse it using
7
8
      the normal infix syntax.  It also has an option to display
      formulas using LBT's syntax.
9

10
11
12
13
14
15
    - ltl2tgba and dstar2tgba have a new experimental option --hoaf to
      output automata in the Hanoï Omega Automaton Format whose
      current draft is at http://adl.github.io/hoaf/
      The corresponding C++ function is spot::hoaf_reachable() in
      tgbaalgos/hoaf.hh.

16
17
    - 'randltl 4' is now a shorthand for 'randltl p0 p1 p2 p3'.

18
19
20
21
    - ltlcross has a new option --save-bogus=FILENAME to save any
      formula for which a problem (other than timeout) was detected
      during translation or using the resulting automatas.

22
  * Documentation:
23
24
25
26

    - The man page for ltl2tgba has some new notes and references
      about TGBA and about monitors.

27
28
  * Bug fixes:

29
30
31
32
    - Fix incorrect simplification of promises in the translation
      of the M operator (you may suffer from the bug even if you do
      not use this operator as some LTL patterns are automatically
      reduced to it).
33
    - Fix simplification of bounded repetition in SERE formulas.
34
35
36
    - Fix incorrect translation of PSL formulas of the form !{f} where
      f is unsatisifable.  A similar bug was fixed for {f} in Spot
      1.1.4, but for some reason it was not fixed for !{f}.
37
    - Fix parsing of neverclaims produced by Modella.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
38
39
40
    - Fix a memory leak in the little-used conversion from
      transition-based alternating automata to tgba.
    - Fix a harmless uninitialized read in BuDDy.
41
42
43
44
45
    - When writing to the terminal, ltlcross used to display each
      formula in bright white, to make them stand out.  It turns out
      this was actually hiding the formulas for people using a
      terminal with white background... This version displays formula
      in bright blue instead.
46
47
48
49
    - 'randltl -n -1 --seed 0' and 'randltl -n -1 --seed 1' used to
      generate nearly the same list of formulas, shifted by one,
      because the PRNG write reset with an incremented seed between
      each output formula.  The PRNG is now reset only once.
50

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
51
New in spot 1.2.4 (2014-05-15)
52

53
54
55
  * New features:

    - "-B -x degen-lskip" can be used to disable level-skipping in the
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
56
57
      degeralization procedure called by ltl2tgba and dstar2tgba.
      This is mostly meant for running experiments.
58
59
60
61
62
63
    - "-B -x degen-lcache=N" can be used to experiment with different
      type of level caching during degeneralization.

  * Bug fixes:

    - Change the Python bindings to make them compatible with Swig 3.0.
64
65
66
    - "ltl2tgta --ta" could crash in certain conditions due to the
      introduction of a simulation-based reduction after
      degeneralization.
67
68
69
70
71
    - Fix four incorrect formula-simplification rules, three were
      related to the factorization of Boolean subformulas in
      operands of the non-length-matching "&" SERE operator, and
      a fourth one could only be enabled by explicitely passing the
      favor_event_univ option to the simplifier (not the default).
72
73
    - Fix incorrect translation of the fusion operator (":") in SERE
      such as {xx;1}:yy[*] where the left operand has 1 as tail.
74

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
75
New in spot 1.2.3 (2014-02-11)
76

77
78
79
80
81
82
  * New features:

    - The SPOT_SATLOG environment variable can be set to a filename to
      obtain statistics about the different iterations of the
      SAT-based minimization.  For an example, see
      http://spot.lip6.fr/userdoc/satmin.html
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
83
84
    - The bench/dtgbasat/ benchmark has been updated to use SPOT_SATLOG
      and record more statistics.
85
86
87
88
    - The default value for the SPOT_SATSOLVER environment
      variable has been changed to "glucose -verb=0 -model %I >%O".
      This assumes that glucose 3.0 is installed.   For older
      versions of glucose, remove the "-model" option.
89

90
91
92
  * Bug fixes:

    - More fixes for Python 3 compatibility.
93
94
95
    - Fix calculation of length_boolone(), were 'Xa|b|c' was
      considered as length 6 instead of 4 (because it is 'Xa|(b|a)'
      were (b|a) is Boolean).
96
97
98
99
    - Fix Clang-3.5 warnings.
    - randltl -S did not honor --boolean-priorities.
    - randltl had trouble generating formulas when all unary, or
      all binary/n-ary operators were disabled.
100
    - Fix spurious testsuite failure when using Pandas 0.13.
101
102
103
104
105
    - Add the time spent in child processes when measuring time
      with the timer class.
    - Fix determinism of the SAT-based minimization encoding.
      (It would sometimes produce different equivalent automata,
      because of a different encoding order.)
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
106
107
    - If the SAT-based minimization is asked for a 10-state automaton
      and returns a 6-state automaton, do not ask for a 9-state
108
      automaton in the next iteration...
109
110
111
112
    - Fix some compilation issue with the version of Apple's Clang
      that is installed with MacOS X 10.9.
    - Fix VPATH builds when building from the git repository.
    - Fix UP links in the html documentation for command-line tools.
113

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
114
New in spot 1.2.2 (2014-01-24)
115

116
117
118
119
120
121
122
123
  * Bug fixes:

    - Fix compilation *and* behavior of bitvectors on 32-bit
      architectures.
    - Fix some compilation errors observed using the antique G++ 4.0.1.
    - Fix compatibility with Python 3 in the test suite.
    - Fix a couple of new clang warnings (like "unused private member").
    - Add some missing #includes that are not included indirectly
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
124
      when the C++ compiler is in C++11 mode.
125
126
127
128
    - Fix detection of numbers that are too large in the ELTL parser.
    - Fix a memory leak in the ELTL parser, and avoid some unnecessary
      calls to strlen() at the same time.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
129
New in spot 1.2.1 (2013-12-11)
130

131
  * New features:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
132

133
134
135
136
137
138
    - commands for translators specified to ltlcross can now
      be given "short names" to be used in the CSV or JSON output.
      For instance
         ltlcross '{small} ltl2tgba -s --small %f >%N' ...
      will run the command "ltl2tgba -s --small %f >%N", but only
      print "small" in output files.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
139

140
141
142
143
144
145
146
    - ltlcross' CSV and JSON output now contains two additional
      columns: exit_status and exit_code, used to report failures of
      the translator.  If the translation failed, only the time is
      reported, and the rest of the statistics, which are missing,
      area left empty (in CVS) or null (in JSON).  A new option,
      --omit-missing can be used to remove lines for failed
      translations, and remove these two columns.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
147

148
149
150
    - if ltlcross is used with --products=+5 instead of --products=5
      then the stastics for each of the five products will be output
      separately instead of being averaged.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
151

152
153
154
155
156
    - if ltlcross is used with tools that produce deterministic Streett
      or Rabin automata (as specified with %D), then the statistics
      output in CSV or JSON will have some extra columns to report
      the size of these input automata before ltlcross converts them
      into TGBA to perform its regular checks.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
157

158
159
160
161
    - ltlfilt, ltl2tgba, ltl2tgta, and ltlcross can now read formulas
      from CSV files.  Use option -F FILE/COL to read formulas from
      column COL of FILE.  Use -F FILE/-COL if the first line of
      FILE be ignored.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
162

163
164
165
166
167
    - when ltlfilt processes formulas from a CSV file, it will output
      each CSV line whose formula matches the given constraints, with
      the rewriten formula.  The new escape sequence %< (text in
      columns before the formula) and %> (text after) can be used
      with the --format option to alter this output.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
168

169
170
    - ltlfile, genltl, randltl, and ltl2tgba have a --csv-escape option
      to help escape formulas in CSV files.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
171

172
173
174
    - Please check
            http://spot.lip6.fr/userdoc/csv.html
      for some discussion and examples of the last few features.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
175

176
  * Bug fixes:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
177

178
179
180
181
182
183
    - ltlcross' CSV output has been changed to be more RFC 4180
      compliant: it no longuer output useless cosmetic spaces, and
      use double-quotes with proper escaping for strings.  The only
      RFC 4180 rule that it does not follow is that it will terminate
      lines with \n instead of \r\n because the latter cause issues
      with a couple of tools.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
184

185
186
    - ltlcross failed to report missing input or output escape sequences
      on all but the first configured translator.
187

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
188
New in spot 1.2 (2013-10-01)
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
189

190
191
192
193
194
195
196
197
  * Changes to command-line tools:

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

    - 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.
198

199
200
    - ltlcross can now read the Rabin and Streett automata output by
      ltl2dstar.  This type of output should be specified using '%D':
201

202
        ltlcross 'ltl2dstar --ltl2nba=spin:path/to/ltl2tgba@-s %L %D'
203

204
      However because Spot only supports Büchi acceptance, these Rabin
205
      and Streett automata are immediately converted to TGBAs before
206
207
      further processing by ltlcross.  This is still interesting to
      search for bugs in translators to Rabin or Streett automata, but
208
      the statistics (of the resulting TGBAs) might not be very relevant.
209

210
211
212
213
214
215
    - When ltlcross obtains a deterministic automaton from a
      translator it will now complement this automaton to perform
      additional intersection checks.  This is complementation is done
      only for deterministic automata (because that is cheap) and can
      be disabled with --no-complement.

216
217
218
219
    - To help with debugging problems detected by ltlcross, the
      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 details.
220

221
    - There is a new command, named dstar2tgba, that converts a
222
223
224
225
226
227
228
229
230
231
232
233
      deterministic Rabin or Streett automaton (expressed in the
      output format of ltl2dstar) into a TGBA, BA or Monitor.

      In the case of Rabin acceptance, the conversion will output a
      deterministic Büchi automaton if one such automaton exist.  Even
      if no such automaton exists, the conversion will actually
      preserves the determinism of any SCC that can be kept
      deterministic.

      In the case of Streett acceptance, the conversion produces
      non-deterministic Büchi automata with Generalized acceptance.
      These are then degeneralized if requested.
234

235
236
237
      See http://spot.lip6.fr/userdoc/dstar2tgba.html for some
      examples, and the man page for more reference.

238
239
240
241
242
    - The %S escape sequence used by ltl2tgba --stats to display the
      number of SCCs in the output automaton has been renamed to %c.
      This makes it more homogeneous with the --stats option of the
      new dstar2tgba command.

243
      Additionally, the %p escape can now be used to show whether the
244
245
246
      output automaton is complete, and the %r escape will give the
      number of seconds spent building the output automaton (excluding
      the time spent parsing the input).
247

248
249
250
251
252
    - ltl2tgba, ltl2tgta, and dstar2tgba have a --complete option
      to output complete automata.

    - ltl2tgba, ltl2tgta, and dstar2tgba can use a SAT-solver to
      minimize deterministic automata.  Doing so is only needed on
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
253
254
      properties that are stronger than obligations (for obligations
      our WDBA-minimization procedure will return a minimimal
255
256
257
      deterministic automaton more efficiently) and is disabled by
      default.  See the spot-x(7) man page for documentation about the
      related options: sat-minimize, sat-states, sat-acc, state-based.
258
259
      See also http://spot.lip6.fr/userdoc/satmin.html for some
      examples.
260

261
262
263
264
    - ltlfilt, genltl, and randltl now have a --latex option to output
      formulas in a way that its easier to embed in a LaTeX document.
      Each operator is output as a command such as \U, \F, etc.
      doc/tl/spotltl.sty gives one possible definition for each macro.
265

266
267
268
269
    - ltlfilt, genltl, and randltl have a new --format option to
      indicate how to present the output formula, possibly with
      information about the input.

270
271
272
273
274
    - ltlfilt as a new option, --relabel-bool, to abstract independent
      Boolean subformulae as if they were atomic propositions.
      For instance "a & GF(c | d) & b & X(c | d)" would be rewritten
      as "p0 & GF(p1) & Xp1".

275
  * New functions and classes in the library:
276

277
278
    - dtba_sat_synthetize(): Use a SAT-solver to build an equivalent
      deterministic TBA with a fixed number of states.
279

280
281
    - dtba_sat_minimize(), dtba_sat_minimize_dichotomy(): Iterate
      dtba_sat_synthetize() to reduce the number of states of a TBA.
282

283
284
    - dtgba_sat_synthetize(), dtgba_sat_minimize(),
      dtgba_sat_minimize_dichotomy(): Likewise, for deterministic TGBA.
285

286
    - is_complete(): Check whether a TGBA is complete.
287

288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
    - tgba_complete(): Complete an automaton by adding a sink state
      if needed.

    - dtgba_complement(): Complement a deterministic TGBA.

    - satsolver(): Run an (external) SAT solver, honoring the
      SPOT_SATSOLVER environment variable if set.

    - tba_determinize(): Run a power-set construction, and attempt
      to fix the acceptance simulation to build a deterministic TBA.

    - dstar_parse(): Read a Streett or Rabin automaton in
      ltl2dstar's format.  Note that this format allows only
      deterministic automata.

    - nra_to_nba(): Convert a (possibly non-deterministic) Rabin
      automaton to a non-deterministic Büchi automaton.

    - dra_to_ba(): Convert a deterministic Rabin automaton to a Büchi
      automaton, preserving acceptance in all SCCs where this is possible.

    - nsa_to_tgba(): Convert a (possibly non-deterministic) Streett
      automaton to a non-deterministic TGBA.

    - dstar_to_tgba(): Convert any automaton returned by dstar_parse()
      into a TGBA.

    - build_tgba_mask_keep(): Build a masked TGBA that shows only
      a subset of states of another TGBA.

    - build_tgba_mask_ignore(): Build a masked TGBA that ignore
      a subset of states of another TGBA.

    - class tgba_proxy: Helps writing on-the-fly algorithms that
      delegate most of their methods to the original automaton.

    - class bitvect: A dynamic bit vector implementation.

    - class word: An infinite word, stored as prefix + cycle, with a
      simplify() methods to simplify cycle and prefix in obvious ways.

    - class temporary_file: A temporary file.  Can be instanciated with
      create_tmp_file() or create_open_tmpfile().

    - count_state(): Return the number of states of a TGBA.  Implement
      a couple of specializations for classes where is can be know
      without exploration.

336
337
    - to_latex_string(): Output a formula using LaTeX syntax.

338
339
340
    - relabel_bse(): Relabeling of Boolean Sub-Expressions.
      Implements ltlfilt's --relabel-bool option describe above.

341
342
343
344
345
  * Noteworthy internal changes:

    - When minimize_obligation() is not given the formula associated
      to the input automaton, but that automaton is deterministic, it
      can still attempt to call minimize_wdba() and check the correcteness
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
346
347
      using dtgba_complement().  This allows dstar2tgba to apply
      WDBA-minimization on deterministic Rabin automata.
348
349
350

    - tgba_reachable_iterator_depth_first has been redesigned to
      effectively perform a DFS.  As a consequence, it does not
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
351
      inherit from tgba_reachable_iterator anymore.
352

353
354
355
356
    - postproc::set_pref() was used to accept an argument among Any,
      Small or Deterministic.  These can now be combined with Complete
      as Any|Complete, Small|Complete, or Deterministic|Complete.

357
358
359
360
361
    - operands of n-ary operators (like & and |) are now ordered so
      that Boolean terms come first.  This speeds up syntactic
      implication checks slightly.  Also, literals are now sorted
      using strverscmp(), so that p5 comes before p12.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
362
363
364
365
    - Syntactic implication checks have been generalized slightly
      (for instance 'a & b & F(a & b)' is now reduced to 'a & b'
      while it was not changed in previous versions).

366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
    - All the parsers implemented in Spot now use the same type to
      store locations.

    - 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

  * Bug fixes:

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

    - Configuring with --enable-optimization would reset the value of
      CXXFLAGS.
397

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
398

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
399
New in spot 1.1.4 (2013-07-29)
400

401
402
403
404
405
  * 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
406
407
      parse further neverclaims after the first failure.
    - Add a missing newline in some error message of ltlcross.
408
409
410
411
412
413
414
    - 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
415
    - Various typos.
416

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
417
New in spot 1.1.3 (2013-07-09)
418

419
420
421
422
423
424
425
426
  * 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.
427
    - A memory corruption in ltlcross.
428

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
429
New in spot 1.1.2 (2013-06-09)
430

431
432
433
434
435
  * 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.
436

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
437
New in spot 1.1.1 (2013-05-13):
438

439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
  * 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).

463
464
465
466
467
468
    - 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.

469
470
471
472
473
474
475
476
477
    - 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.

478
479
480
    - ltlcross has a new option --seed, that makes it possible to
      change the seed used by the random graph generator.

481
482
483
484
485
486
487
488
    - 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.

489
490
491
492
    - 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.

493
  * Bug fixes:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
494
495

    - genltl --gh-r generated the wrong formulas due to a typo.
496
497
    - ltlfilt --eventual and --universal were not handled properly.
    - ltlfilt --stutter-invariant would trigger an assert on PSL formulas.
498
499
    - ltl2tgba, ltl2tgta, ltlcross, and ltlfilt, would all choke on empty
      lines in a file of formulas.  They now ignore empty lines.
500
501
502
503
504
505
506
507
    - 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.
508

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
509
New in spot 1.1 (2013-04-28):
510

511
512
513
514
515
516
517
  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.

518
  * New features in the library:
519

520
521
522
    - 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
523
524
      postprocessings.

525
526
527
528
529
530
    - 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.

531
532
533
534
    - 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
535
      disabled by default.  (See SPIN'13 paper.)
536
537
538
539

    - 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
540
      simplified previously.  (See SPIN'13 paper.)
541

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
542
543
544
545
546
547
548
549
550
    - 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.

551
552
553
554
555
    - 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.

556
557
558
559
560
561
562
563
564
565
566
    - 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.

567
568
569
570
571
572
573
574
575
576
577
578
579
    - 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.

580
  * Command-line tools:
581
582

    - ltl2tgba and ltl2tgta now honor a new --extra-options (or -x)
583
584
585
      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.
586

587
588
589
590
591
592
    - 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).

593
594
595
596
    - 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.

597
  * Documentation:
598
599
600
601
602
603

    - 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
604
605
606
607
608
609
610
611
612
613
  * 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.

614
615
  * Bug fixes:

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
616
617
    - There was a memory leak in the LTL simplification code, that could
      only be triggered when disabling advanced simplifications.
618

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
619
620
    - The translation of the PSL formula !{xxx} was incorrect when xxx
      simplified to false.
621

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
622
    - Various warnings triggered by new compilers.
623

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
624
New in spot 1.0.2 (2013-03-06):
625

626
627
628
629
  * 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.
630
631
632
633
634
635
636
637
638
639
    - 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.
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
  * 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.
659

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
660
New in spot 1.0.1 (2013-01-23):
661

662
663
664
665
666
667
668
669
670
  * 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.
671
672
673
674
    - "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.
675
676
    - 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
677
678
    - tgba_product::transition_annotation() would segfault when
      called in a product against a Kripke structure.
679
680
681
682
683
684
  * 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)
685
686
    - The on-line version of ltl2tgba now displays edge and
      transition counts, just as the ltlcross tool.
687
688
    - ltlcross will display the number of timeouts at the end
      of its execution.
689
690
    - ltlcross will diagnose tools with missing input or
      output %-sequence before attempting to run any of them.
691
692
693
694
    - 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.
695
696
697
698
699
700
701
702
703
704
705
706
707
  * 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.
708

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
709
New in spot 1.0 (2012-10-27):
710

711
712
713
714
  * 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+.

715
716
717
718
  * 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
719
    suite and had evolved organically into useful programs with crappy
720
721
722
    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
723
    - genltl:   Generate LTL formulas from scalable patterns.
724
725
726
727
728
729
                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
730
731
732
733
734
		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, ...
735

736
    - ltl2tgba: Translate LTL/PSL formulas into Büchi automata (TGBA,
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
737
                BA, or Monitor).  A fundamental change to the
738
739
740
                interface is that you may now specify the goal of the
                translation: do you you favor deterministic or smaller
                automata?
741
742
743

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

744
    - ltlcross: Compare the output of translators from LTL/PSL to
745
746
747
748
                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.
749

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
750
751
752
753
754
    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
755
    gazillion options is still in src/tgbatest/ and is meant to be
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
756
757
758
    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.
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788

  * 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
789
      PhD work, should appear in ToPNoC VI (LNCS 7400).  The web-based
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
790
      interface and the aforementioned ltl2tgta tool can be used
791
      to build testing automata.
792
793
794
795
796
797
798

    - 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.

799
    - The enumerate_cycles class implements the Loizou-Thanisch
800
801
802
803
      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).
804
805
806
807
808
809

    - 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.

810
811
812
    - to_wring_string() can be used to print an LTL formula into
      Wring's syntax.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
813
    - The LTL/PSL parser now has a lenient mode that can be useful
814
815
816
817
818
819
820
      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.

821
822
823
    - 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
824
      choosing between less states or more determinism.
825
826
827
828
829
830

    - 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
831
      all available simplification algorithms on a TGBA/BA/Monitors.
832
833
834
835
836
837
838
839

  * 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.

840
841
842
843
844
845
846
    - 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).

847
848
849
    - The gspn-ssp benchmark has been removed.


Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
850
New in spot 0.9.2 (2012-07-02):
851

852
853
854
  * 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.
855
856
857
858
859
  * 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
860
      BuDDy to check whether one BDD implies another.  This benefits
861
      mostly the simulation and degeneralization algorithms of Spot.
862
863
864
    - A new offline implementation of the degeneralization (which
      had always been performed on-the-fly so far) available.  This
      especially helps the Safra complementation.
865
866
867
  * Bug fixes:
    - The CGI script running for ltl2tgba.html will correctly timeout
      after 30s when Spot's translation takes more time.
868
869
870
871
872
873
    - 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).
874
    - Better error recovery when parsing broken LTL formulae.
875
876
    - Fix errors and warnings reported by clang 3.1 and the
      upcoming g++ 4.8.
877

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
878
New in spot 0.9.1 (2012-05-23):
879

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
880
  * The version of LBTT we distribute includes a patch from Tomáš
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
    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.
896
897
  * The tgba_parse() function is now available via the Python
    bindings.
898
899
900
  * Bug fixes:
    - The random SERE generator was using the wrong operators
      for "and" and "or", mistaking And/Or with AndRat/OrRat.
901
902
    - The translation of !{r} was incorrect when this subformula
      was recurring (e.g. in G!{r}) and r had loops.
903
    - Correctly recognize ltl2tgba's option -rL.
904
905
906
907
908
909
910
    - 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.
911

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
912
New in spot 0.9 (2012-05-09):
913

914
  * New features:
915
916
917
918
919
920
921
922
923
    - 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
924
      (for instance to rewrite "{a;b;c}" into "a & X(b & Xc)")
925
926
927
928
929
930
931
932
      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
933
934
935
936
937
938
939
      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.
940
    - A new direct simulation reduction has been implemented.  It
941
      works directly on TGBAs.  It is in src/tgbaalgos/simlation.hh,
942
      and it can be tested via ltl2tgba's -RDS option.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
943
    - unabbreviate_wm() is a function that rewrites the W and M operators
944
945
946
947
948
      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.
949
950
951
    - changes to the on-line translator:
      + SVG output is available
      + can display some properties of a formula
952
953
      + new options for direct simulation, larger rewritings, and
        utf-8 output
954
955
956
957
    - 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.
958
  * Interface changes:
959
    - Operators ->, <->, U, W, R, and M are now parsed as
960
      right-associative to better match the PSL standard.
961
962
963
964
965
966
967
968
969
970
971
972
973
974
    - 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.
975
976
977
978
    - 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.
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
    - 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.
994

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
995
New in spot 0.8.3 (2012-03-09):
996

997
998
  * Support for both Python 2.x and Python 3.x.
    (Previous versions would only work with Python 2.x.)
999
1000
  * The online ltl2tgba.html now stores its state in the URL so that
    history is preserved, and links to particular setups can be sent.
1001
1002
1003
1004
  * 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
1005
    - Fix a segfault in the CGI script when computing a Büchi run.
1006

1007
New in spot 0.8.2 (2012-01-19):
1008

1009
1010
  * configure now has a --disable-python option to disable
    the compilation of Python bindings.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1011
  * Minor speedups in the Safra complementation.
1012
  * Better memory management for the on-the-fly degeneralization
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1013
    algorithm.  This mostly benefits to the Safra complementation.
1014
1015
1016
  * Bug fixes:
    - spot::ltl::length() forgot to count the '&' and '|' operators
      in an LTL formula.
1017
1018
    - 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
1019
    - minimize_dfa() could produce incorrect automata, but it is not
1020
1021
1022
      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).
1023
    - Fix a Python syntax error in the CGI script.
1024
1025
    - Fix compilation with g++ 4.0.
    - Fix a make check failure when valgrind is missing.
1026

1027
New in spot 0.8.1 (2011-12-18):
1028

1029
1030
1031
1032
1033
1034
1035
1036
  * 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.
1037

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1038
New in spot 0.8 (2011-11-28):
1039

1040
1041
  * Major new features:
    - Spot can read DiVinE models.  See iface/dve2/README for details.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1042
    - The genltl tool can now output 20 different LTL formula families.
1043
      It also replaces the LTLcounter Perl scripts.
1044
    - There is a printer and parser for Kripke structures in text format.
1045
1046
1047
1048
1049
  * 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.
1050
    - The experimental Nips interface has been removed.
1051
1052
1053
1054
1055
1056
  * 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.
1057
1058
1059
    - 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.
1060
1061
1062
    - 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
1063
    - The Doxygen documentation is no longer built as a PDF file.
1064
1065
1066
  * Internal improvements:
    - The on-line ltl2tgba CGI script uses a cache to produce faster
      answers.
1067
1068
1069
    - Better memory management for the states of explicit automata.
      Thanks to the aforementioned ->destroy() change, we can avoid
      cloning explicit states.
1070
1071
1072
1073
    - 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.
1074
1075
1076
1077
1078
    - 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.
1079
    - The degeneralization is now idempotent.  Previously, degeneralizing
1080
1081
1082
1083
      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.
1084
1085
1086
1087
1088
1089
1090
1091
    - 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).
1092

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1093
New in spot 0.7.1 (2011-02-07):
1094

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1095
1096
1097
1098
1099
1100
  * 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
1101
        :: (!(...)) -> goto ...
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1102
1103
    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
1104
    I.e., a transition labelled by "true" counts for 4 "sub-transitions"
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1105
1106
1107
    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
1108
    - Use the included BuDDy library if the one already installed
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1109
1110
      is older than the one distributed with Spot 0.7.
    - Fix two typos in the code of the CGI scripts.
1111

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1112
New in spot 0.7 (2011-02-01):
1113

1114
1115
1116
1117
1118
  * 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.
1119
1120
1121
  * 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.
1122
1123
  * src/ltltest/genltl is a new tool that generates some interesting
    families of LTL formulae, for testing purpose.
1124
  * bench/ltlclasses/ uses the above tool to conduct the same benchmark
1125
    as in the DepCoS'09 paper by Cichoń et al.  The resulting benchmark
1126
1127
    completes in 12min, while it tooks days (or exhausted the memory)
    when the paper was written (they used Spot 0.4).
1128
  * Degeneralization has again been improved in two ways:
1129
    - It will merge degeneralized transitions that can be merged.
1130
    - It uses a cache to speed up the improvement introduced in 0.6.
1131
1132
  * An implementation of Dax et al.'s paper for minimizing obligation
    formulae has been integrated.  Use ltl2tgba -Rm to enable this
1133
1134
    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
1135
1136
  * bench/wdba/ conducts a benchmark similar to the one on Dax's
    webpage, comparing the size of the automata expressing obligation
1137
1138
    formula before and after minimization.  See bench/wdba/README for
    results.
1139
  * Using similar code, Spot can now construct deterministic monitors.
1140
1141
1142
1143
  * 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
1144
1145
             replayed on the automaton to ensure it is correct
	     (previous version would always compute a replay a
1146
1147
	     counterexample when emptiness-check was enabled)
    -ks: traverse the automaton to compute its number of states and
1148
         transitions (this is faster than -k which will also count
1149
         SCCs and paths).
1150
    -M: Build a deterministic monitor.
1151
1152
1153
    -O: Tell whether a formula represents a safety, guarantee, or
        obligation property.
    -Rm: Minimize automata representing obligation properties.
1154
1155
1156
  * 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.
1157
1158
1159
1160
1161
  * 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.
1162
    - The formula simplification based on universality and eventuality
1163
      had a quadratic run-time.
1164

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1165
New in spot 0.6 (2010-04-16):
1166

1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
  * 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.
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
  * 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.
1195
1196
1197
1198
1199
1200
1201
  * 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
1202
      Spot >= 0.6 will parse it as "(a & b) -> (c & d)".
1203
1204
1205
    - 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.
1206

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1207
New in spot 0.5 (2010-02-01):
1208
1209
1210
1211
1212

  * 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
1213
    - <spot@lrde.epita.fr> can be used to discuss anything related
1214
1215
1216
      to Spot.  You may subscribe at
      https://www.lrde.epita.fr/mailman/listinfo/spot-announce
  * Two new LTL translations have been implemented:
1217
1218
1219
1220
1221
    - 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.
1222
1223
    - ltl_to_taa() is a translation based on Tauriainen's PhD thesis.
      LTL is translated to "self-loop" alternating automata
1224
1225
      and then to Transition-based Generalized Automata.  (ltl2tgba's
      option -taa).
1226
1227
1228
1229
1230
    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.
1231
  * Two complementation algorithms for state-based Büchi automata
1232
    have been implemented:
1233
    - tgba_kv_complement is an on-the-fly implementation of the
1234
1235
1236
      Kupferman-Vardi construction (TCS'05) for generalized acceptance
      conditions.
    - tgba_safra_complement is an implementation of Safra's
1237
1238
      complementation.  This algorithm takes a degeneralized Büchi
      automaton as input, but our implementation for the Streett->Büchi
1239
1240
1241
      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
1242
    for details.  Couvreur/FM is now the default translation.
1243
  * The ltl2tgba.py CGI script can now run standalone.  It also offers
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1244
1245
    the Tauriainen/TAA translation, and some options for SCC-based
    reductions.
1246
1247
1248
1249
1250
  * 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.
1251
1252
1253
  * 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
1254
  * More benchmarks in the bench/ directory:
1255
1256
1257
1258
1259
1260
1261
    - 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
1262
    conditions and that have label on states instead of transitions.
1263
    This interface has not been used yet.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1264
  * Experimental interface with the Nips virtual machine.
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
    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.
1282

1283
New in spot 0.4 (2007-07-17):
1284

1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
  * 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):
1296
1297
1298
1299
1300
1301
1302

  * 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.

1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
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.
1315

1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
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.
1342

1343
1344
1345
1346
1347
1348
1349
1350
1351
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).
1352

1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
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.
1375

1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
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.
1387

1388
1389
1390
1391
1392
1393
1394
1395
1396
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
1397

1398
1399
1400
1401
1402
1403
1404
1405
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.
1406

1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417