NEWS 101 KB
Newer Older
1
2
New in spot 1.99.4a (not yet released)

3
4
5
  Command-line tools:

  * autfilt has gained a --complement option.
6
    It currently works only for deterministic automata.
7

8
9
10
11
12
13
14
15
  * By default, autfilt does not simplify automata (this has not
    changed), as if the --low --any options where used.  But now, if
    one of --small, --deterministic, or --any is given, the
    optimization level automatically defaults to --high (unless
    specified otherwise).  For symmetry, if one of --low, --medium, or
    --high is given, thn the translation intent defaults to --small
    (unless specified otherwise).

16
17
18
  * ltlgrind FILENAME[/COL] is now the same as
    ltlgrind -F FILENAME[/COL] for consistency with ltlfilt.

19
20
  Library:

21
  * Rename dtgba_complement() to dtwa_complement(), rename the header
22
23
24
25
26
27
28
29
30
    as complement.hh, and restrict the purpose of this function to
    just complete the automaton and complement its acceptance
    condition.   Any further acceptance condition transformation
    can be done with to_generalized_buchi() or remove_fin().

  * The remove_fin() has learnt how to better deal with automata that
    are declared as weak.  This code was previously in
    dtgba_complement().

31
32
33
34
35
36
37
38
  * scc_filter_states() has learnt to remove useless acceptance marks
    that are on transitions between SCCs, while preserving state-based
    acceptance.  The most visible effect is in the output of "ltl2tgba
    -s XXXa": it used to have 5 accepting states, it now has only one.
    (Changing removing acceptance of those 4 states has no effect on
    the language, but it speedup some algorithms like NDFS-based
    emptiness checks, as discussed in our Spin'15 paper.)

39
40
41
  * The HOA parser will diagnose any version that is not v1, unless it
    looks like a subversion of v1 and no parse error was detected.

42
43
  * ltl_simplifier renamed to tl_simplifier.

44
45
  Python:

46
  * The minimum supported Python version is now 3.3.
47
  * Add bindings for complete() and dtwa_complement()
48
49
  * Formulas now have a custom __format__ function.  See
    https://spot.lrde.epita.fr/tut01.html for examples.
50
51
  * The Debian package is now compiled for all Python3 versions
    supported by Debian, not just the default one.
52
  * Automata now have get_name()/set_name() methods.
53
54
55
  * spot.postprocess(aut, *options), or aut.postprocess(*options)
    simplify the use of the spot.postprocessor object.  (Just like we
    have spot.translate() on top of spot.translator().)
56
57
58
  * spot.automata() and spot.automaton() now have an optional
    timeout argument to restrict the runtime of commands that
    produce automata.
59
60
61

  Bugs fixed:

62
  * Work around some weird exception raised when using the
63
64
65
66
67
    randltlgenerator under Python 3.5.
  * Recognize "nullptr" formulas as None in Python.
  * Fix compilation of bench/stutter/
  * Handle saturation of formula reference counts.
  * Fix typo in the Python code for the CGI server.
68
  * "randaut -Q0 1" used to segfault.
69
70
  * "ltlgrind -F FILENAME/COL" did not preserve other CSV columns.
  * "ltlgrind --help" did not document FORMAT.
71
  * unabbreviate could easily use forbidden operators.
72
73
  * "autfilt --is-unambiguous" could fail to detect the nonambiguity
    of some automata with empty languages.
74
75
76
  * When parsing long tokens (e.g, state labels representing
    very large strings) the automaton parser could die with
    "input buffer overflow, can't enlarge buffer because scanner uses REJECT"
77

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
78
New in spot 1.99.4 (2015-10-01)
79

80
81
  New features:

82
83
84
85
  * autfilt's --sat-minimize now takes a "colored" option to constrain
    all transitions (or states) in the output automaton to belong to
    exactly one acceptance sets.  This is useful when targeting parity
    acceptance.
86

87
88
89
90
91
92
93
94
95
96
  * autfilt has a new --product-or option.  This builds a synchronized
    product of two (completed of needed) automata in order to
    recognize the *sum* of their languages.  This works by just using
    the disjunction of their acceptance conditions (with appropriate
    renumbering of the acceptance sets).

    For consistency, the --product option (that builds a synchronized
    product that recognizes the *intersection* of the languages) now
    also has a --product-and alias.

97
98
99
100
101
102
103
104
105
106
  * the parser for ltl2dstar's format has been merged with the parser
    for the other automata formats.  This implies two things:
    - autfilt and dstar2tgba (despite its name) can now both read
      automata written in any of the four supported syntaxes
      (ltl2dstar's, lbtt's, HOA, never claim).
    - "dstar2tgba some files..." now behaves exactly like
      "autfilt --tgba --high --small some files...".
      (But dstar2tgba does not offer all the filtering and
      transformations options of autfilt.)

107
108
  Major code changes and reorganization:

109
110
111
  * The class hierarchy for temporal formulas has been entirely
    rewritten.  This change is actually quite massive (~13200 lines
    removed, ~8200 lines added), and brings some nice benefits:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
112
    - LTL/PSL formulas are now represented by lightweight formula
113
114
115
116
      objects (instead of pointers to children of an abstract
      formula class) that perform reference counting automatically.
    - There is no hierachy anymore: all operators are represented by
      a single type of node in the syntax tree, and an enumerator is
117
      used to distinguish between operators.
118
119
120
121
122
123
124
125
    - Visitors have been replaced by member functions such as map()
      or traverse(), that take a function (usually written as a
      lambda function) and apply it to the nodes of the tree.
    - As a consequence, writing algorithms that manipulate formula
      is more friendly, and several algorithms that spanned a few
      pages have been reduced to a few lines.
    The page https://spot.lrde.epita.fr/tut03.html illustrates the
    new interface, in both C++ and Python.
126

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
127
128
129
130
131
  * Directories ltlast/, ltlenv/, and ltlvisit/, have been merged into
    a single tl/ directory (for temporal logic).  This is motivated by
    the fact that these formulas are not restricted to LTL, and by the
    fact that we no longuer use the "visitor" pattern.

132
133
134
  * The LTL/PSL parser is now declared in tl/parse.hh (instead of
    ltlparse/public.hh).

135
136
137
138
139
140
141
142
143
144
145
  * The spot::ltl namespace has been merged with the spot namespace.

  * The dupexp_dfs() function has been renamed to copy(), and has
    learned to preserve named states if required.

  * Atomic propositions can be declared without going through an
    environment using the spot::formula::ap() static function.  They
    can be registered for an automaton directly using the
    spot::twa::register_ap() method.  The vector of atomic
    propositions used by an automaton can now be retrieved using the
    spot::twa::ap() method.
146

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
147
New in spot 1.99.3 (2015-08-26)
148

149
150
151
  * The CGI script for LTL translation offers a HOA download link
    for each generated automaton.

152
  * The html documentation now includes a HTML copies of the man
153
    pages, and HTML copies of the Python notebooks.
154

155
156
157
158
  * scc_filter(aut, true) does not remove Fin marks from rejecting
    SCCs, but it now does remove Fin marks from transitions between
    SCCs.

159
160
161
  * All the unabbreviation functions (unabbreviate_ltl(),
    unabbreviate_logic(), unabbreviate_wm()) have been merged into a
    single unabbreviate() function that takes a string representing
162
163
164
    the list of operators to remove among "eFGiMRW^" where 'e', 'i',
    and '^' stand respectively for <->, ->, and xor.
    This feature is also available via ltlfilt --unabbreviate.
165

166
167
168
169
  * In LTL formulas, atomic propositions specified using double-quotes
    can now include \" and \\.  (This is more consistent with the HOA
    format, which already allows that.)

170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
  * All the conversion routines that were written specifically for
    ltl2dstar's output format (DRA->BA & DRA->TGBA) have been ported
    to the new TωA structure supporting the HOA format.  The DRA->TGBA
    conversion was reimplemented in the previous release, and the
    DRA->BA conversion has been reimplemented in this release (but it
    is still restricted to state-based acceptance).  All these
    conversions are called automatically by to_generalized_buchi()
    or remove_fin() so there should be no need to call them directly.

    As a consequence:
    - "autfilt --remove-fin" or "autfilt -B" is better at converting
      state-based Rabin automata: it will produce a DBA if the input is
      deterministic and DBA-realizable, but will preserve as much
      determinism as possible otherwise.
    - a lot of obsolete code that was here only to support the old
      conversion routines has been removed.  (The number of lines
      removed by this release is twice the number of lines added.)
    - ltlcross now uses automata in ltl2dstar's format directly,
      without converting them to Büchi (this makes the statistics
      reported in CSV files more relevant).
    - ltlcross no longer outputs additional columns about the size
      of the input automaton in the case ltl2dstar's format is used.
    - ltldo uses results in ltl2dstar's format directly, without
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
193
      converting them to Büchi.
194
195
    - dstar2tgba has been greatly simplified and now uses the
      same output routines as all the other tools that output
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
196
      automata.  This implies a few minor semantic changes, for
197
      instance --stats=%A used to output the number of acceptance
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
198
      *pairs* in the input automaton, while it now outputs the
199
200
      number of acceptance sets like in all the other tools.

201
202
  * Bugs fixed
    - Some acceptance conditions like Fin(0)|Fin(1)|Fin(2)&Inf(3)
203
      were not detected as generalized-Rabin.
204
205
    - Unknown arguments for print_hoa() (i.e., option -H in command-line
      tools) are now diagnosed.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
206
    - The CGI script for LTL translation now forces transition-based
207
208
209
210
      acceptance on WDBA-minimized automata when TGBA is requested.
    - ltlgrind --help output had some options documented twice, or
      in the wrong place.
    - The man page for ltlcross had obsolete examples.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
211
212
    - When outputting atomic propositions in double quotes, the
      escaping routine used by the two styles of LaTeX output was
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
213
214
      slightly wrong.  For instance ^ was incorrectly escaped, and
      the double quotes where not always properly rendered.
215
216
    - A spurious assertion was triggered by streett_to_generalized_buchi(),
      but only when compiled in DEBUG mode.
217
    - LTL formula rewritten in Spin's syntax no longer have their ->
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
218
      and <-> rewritten away.
219
    - Fix some warnings reported by the development version of GCC 6.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
220
    - The spot.translate() function of the Python binding had a typo
221
      preventing the use of 'low'/'medium'/'high' as argument.
222
    - Fix spurious failure of uniq.test under different locales.
223
224
    - ltlcross now recovers from out-of-memory errors during
      state-space products.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
225
226
    - bitvect.test was failing on 32bit architectures with
      assertions enabled because of a bug in the test case.
227

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
228
New in spot 1.99.2 (2015-07-18)
229

230
  * The scc_info object, used to build a map of SCCs while gathering
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
231
    additional information, has been simplified and speed up.  One
232
    test case where ltlcross would take more than 13min (to check the
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
233
    translation of one PSL formula) now takes only 75s.
234

235
236
237
  * streett_to_generalized_buchi() is a new function that implements
    what its name suggests, with some SCC-based optimizations over the
    naive definition.  It is used by the to_generalized_buchi() and
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
238
    remove_fin() functions when the input automaton is a Streett
239
240
241
242
243
244
245
246
247
    automaton with more than 3 pairs (this threeshold can be changed
    via the SPOT_STREETT_CONV_MIN environment variable -- see the
    spot-x(7) man page for details).

    This is mainly useful to ltlcross, which has to get rid of "Fin"
    acceptance to perform its checks.  As an example, the Streett
    automaton generatated by ltl2dstar (configured with ltl2tgba) for
    the formula
      !((GFa -> GFb) & (GFc -> GFd))
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
248
249
250
251
    has 4307 states and 14 acceptance sets.  The new algorithm can
    translate it into a TGBA with 9754 states and 7 acceptance sets,
    while the default approch used for converting any acceptance
    to TGBA would produce 250967 states and 7 acceptance sets.
252

253
  * Bugs fixed:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
254
    - p[+][:*2] was not detected as belonging to siPSL.
255
256
    - scc_filter() would incorrectly remove Fin marks from
      rejecting SCCs.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
257
    - the libspotltsmin library is installed.
258
    - ltlcross and ltldo did not properly quote atomic propositions
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
259
260
      and temporary file names containing a single-quote.
    - a missing Python.h is now diagnosed at ./configure time, with
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
261
262
263
264
      the suggestion to either install python3-devel, or run
      ./configure --disable-python.
    - Debian packages for libraries have been split from
      the main Spot package, as per Debian guidelines.
265

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
266
New in spot 1.99.1 (2015-06-23)
267

268
269
270
271
272
  * Major changes motivating the jump in version number

    - Spot now works with automata that can represent more than
      generalized Büchi acceptance.  Older versions were built around
      the concept of TGBA (Transition-based Generalized Büchi
273
      Automata) while this version now deals with what we call TωA
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
      (Transition-based ω-Automata).  TωA support arbitrary acceptance
      conditions specified as a Boolean formula of transition sets
      that must be visited infinitely often or finitely often.  This
      genericity allows for instance to represent Rabin or Streett
      automata, as well as some generalized variants of those.

    - Spot has near complete support for the Hanoi Omega Automata
      format.  http://adl.github.io/hoaf/  This formats supports
      automata with the generic acceptance condition described above,
      and has been implemented in a number of third-party tools (see
      http://adl.github.io/hoaf/support.html) to ease their
      interactions.  The only part of the format not yet implemented in
      Spot is the support for alternating automata.

    - Spot is now compiling in C++11 mode.  The set of C++11 features
      we use requires GCC >= 4.8 or Clang >= 3.5.  Although GCC 4.8 is
      more than 2-year old, people with older installations won't be
      able to install this version of Spot.

293
    - As a consequence of the switches to C++11 and to TωA, a lot of
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
      the existing C++ interfaces have been renamed, and sometime
      reworked.  This makes this version of Spot not backward
      compatible with Spot 1.2.x.  See below for the most important
      API changes.  Furtheremore, the reason this release is not
      called Spot 2.0 is that we have more of those changes planned.

    - Support for Python 2 was dropped.  We now support only Python
      3.2 or later.  The Python bindings have been improved a lot, and
      include some conveniance functions for better integration with
      IPython's rich display system.  User familiar with IPython's
      notebook should have a look at the notebook files in
      wrap/python/tests/*.ipynb

  * Major news for the command-line tools

    - The set of tools installed by spot now consists in the following
      11 commands.  Those marked with a '+' are new in this release.

      - randltl    Generate random LTL/PSL formulas.
      - ltlfilt    Filter and convert LTL/PSL formulas.
      - genltl     Generate LTL formulas from scalable patterns.
      - ltl2tgba   Translate LTL/PSL formulas into Büchi automata.
      - ltl2tgta   Translate LTL/PSL formulas into Testing automata.
      - ltlcross   Cross-compare LTL/PSL-to-Büchi translators.
      + ltlgrind   Mutate LTL/PSL formula.
      - dstar2tgba Convert deterministic Rabin or Streett automata into Büchi.
      + randaut    Generate random automata.
      + autfilt    Filter and convert automata.
      + ltldo      Run LTL/PSL formulas through other tools.

      randaut does not need any presentation: it does what you expect.

      ltlgrind is a new tool that mutates LTL or PSL formulas.  If you
327
      have a tool that is bogus on some formula that is too large to
328
329
330
      debug, you can use ltlgrind to generate smaller derived formulas
      and see if you can reproduce the bug on those.

331
332
333
334
335
336
337
338
339
340
341
342
      autfilt is a new tool that processes a stream of automata.  It
      allows format conversion, filtering automata based on some
      properties, and general transformations (e.g., change of
      acceptance conditions, removal of useless states, product
      between automata, etc.).

      ltldo is a new tool that runs LTL/PSL formulas through other
      tools, but uses Spot's command-line interfaces for specifying
      input and output.  This makes it easier to use third-party tool
      in a pipe, and it also takes care of some necessary format
      conversion.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
343
    - ltl2tgba has a new option, -U, to produce unambiguous automata.
344
345
346
      In unambiguous automata any word is recognized by at most one
      accepting run, but there might be several ways to reject a word.
      This works for LTL and PSL formulas.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
347

348
    - ltl2tgba has a new option, -S, to produce generalized-Büchi
349
350
351
352
353
      automata with state-based acceptance.  Those are obtained by
      converting some transition-based GBA into a state-based GBA, so
      they are usually not as small as one would wish.  The same
      option -S is also supported by autfilt.

354
355
356
357
358
    - ltlcross will work with translator producing automata with any
      acceptance condition, provided the output is in the HOA format.
      So it can effectively be used to validate tools producing Rabin
      or Streett automata.

359
    - ltlcross has several new options:
360

361
362
        --grind attempts to reduce the size of any bogus formula it
        discovers, while still exhibiting the bug.
363

364
365
        --ignore-execution-failures ignores cases where a translator
        exits with a non-zero status.
366
367

	--automata save the produced automata into the CSV or JSON
368
        file.  Those automata are saved using the HOA format.
369
370
371
372
373

      ltlcross will also output two extra columns in its CSV/JSON
      output: "ambiguous_aut" and "complete_aut" are Boolean
      that respectively tells whether the automaton is
      ambiguous and complete.
374

375
    - "ltlfilt --stutter-invariant" will now work with PSL formulas.
376
      The implementation is actually much more efficient
377
      than our previous implementation that was only for LTL.
378

379
380
381
382
383
    - ltlfilt's old -q/--quiet option has been renamed to
      --ignore-errors.  The new -q/--quiet semantic is the
      same as in grep (and also autfilt): disable all normal
      input, for situtations where only the exit status matters.

384
385
386
387
    - ltlfilt's old -n/--negate option can only be used as --negate
      now.  The short '-n NUM' option is now the same as the new
      --max-count=N option, for consistency with other tools.

388
389
390
    - ltlfilt has a new --count option to count the number of matching
      automata.

391
392
393
    - ltlfilt has a new --exclusive-ap option to constrain formulas
      based on a list of mutually exclusive atomic propositions.

394
395
396
397
    - ltlfilt has a new option --define to be used in conjunction with
      --relabel or --relabel-bool to print the mapping between old and
      new labels.

398
399
400
401
402
403
    - all tools that produce formulas or automata now have an --output
      (a.k.a. -o) option to redirect that output to a file instead of
      standard output.  The name of this file can be constructed using
      the same %-escape sequences that are available for --stats or
      --format.

404
405
406
407
    - all tools that output formulas have a -0 option to separate
      formulas with \0.  This helps in conjunction with xargs -0.

    - all tools that output automata have a --check option that
408
409
410
411
412
413
414
415
416
417
      request extra checks to be performed on the output to fill
      in properties values for the HOA format.  This options
      implies -H for HOA output.  For instance
      	ltl2tgba -H 'formula'
      will declare the output automaton as 'stutter-invariant'
      only if the formula is syntactically stutter-invariant
      (e.g., in LTL\X).  With
        ltl2tgba --check 'formula'
      additional checks will be performed, and the automaton
      will be accurately marked as either 'stutter-invariant'
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
418
419
      or 'stutter-sensitive'.  Another check performed by
      --check is testing whether the automaton is unambiguous.
420

421
422
423
424
425
426
    - ltlcross (and ltldo) have a list of hard-coded shorthands
      for some existing tools.  So for instance running
      'ltlcross spin ...' is the same as running
      'ltlcross "spin -f %s>%N" ...'.   This feature is much
      more useful for ltldo.

427
428
    - For options that take an output filename (i.e., ltlcross's
      --save-bogus, --grind, --csv, --json) you can force the file
429
430
      to be opened in append mode (instead of being truncated) by
      by prefixing the filename with ">>".  For instance
431
432
433
      	  --save-bogus=">>bugs.ltl"
      will append to the end of the file.

434
435
  * Other noteworthy news

436
437
438
439
440
441
442
443
    - The web site moved to http://spot.lrde.epita.fr/.

    - We now have Debian packages.
      See http://spot.lrde.epita.fr/install.html

    - The documentation now includes some simple code examples
      for both Python and C++.  (This is still a work in progress.)

444
445
446
447
    - The curstomized version of BuDDy (libbdd) used by Spot has be
      renamed as (libbddx) to avoid issues with copies of BuDDy
      already installed on the system.

448
449
    - There is a parser for the HOA format
      (http://adl.github.io/hoaf/) available as a
450
451
452
453
454
455
      spot::automaton_stream_parser object or spot::parse_aut()
      function.  The former version is able to parse a stream of
      automata in order to do batch processing.  This format can be
      output by all tools (since Spot 1.2.5) using the --hoa option,
      and it can be read by autfilt (by default) and ltlcross (using
      the %H specifier).  The current implementation does not support
456
457
      alternation.  Multiple initial states are converted into an
      extra initial state; complemented acceptance sets Inf(!x) are
458
459
      converted to Inf(x); explicit or implicit labels can be used;
      aliases are supported; "--ABORT--" can be used in a stream.
460

461
462
463
464
465
466
    - The above HOA parser can also parse never claims, and LBTT
      automata, so the never claim parser and the LBTT parser have
      been removed.  This implies that autfilt can input a mix of HOA,
      never claims, and LBTT automata.  ltlcross also use the same
      parser for all these output, and the old %T and %N specifiers
      have been deprecated and replaced by %O (for output).
467

468
469
    - While not all algorithms in the library are able to work with
      any acceptance condition supported by the HOA format, the
470
      following two new functions mitigate that:
471
472
473
474
475
476
477
478
479
480

      - remove_fin() takes a TωA whose accepting condition uses Fin(x)
	primitive, and produces an equivalent TωA without Fin(x):
	i.e., the output acceptance is a disjunction of generalized
	Büchi acceptance.  This type of acceptance is supported by
	SCC-based emptiness-check, for instance.

      - similarly, to_tgba() converts any TωA into an automaton with
	generalized-Büchi acceptance.

481
482
483
    - randomize() is a new algorithm that randomly reorders the states
      and transitions of an automaton.  It can be used from the
      command-line using "autfilt --randomize".
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
484

485
486
    - the interface in iface/dve2 has been renamed to iface/ltsmin
      because it can now interface the dynamic libraries created
487
      either by Divine (as patched by the LTSmin group) or by
488
489
      Spins (the LTSmin compiler for Promela).

490
491
492
493
494
495
496
497
    - LTL/PSL formulas can include /* comments */.

    - PSL SEREs support a new operator [:*i..j], the iterated fusion.
      [:*i..j] is to the fusion operator ':' what [*i..j] is to the
      concatenation operator ';'.  For instance (a*;b)[:*3] is the
      same as (a*;b):(a*;b):(a*;b).  The operator [:+], is syntactic
      sugar for [:*1..], and corresponds to the operator ⊕ introduced
      by Dax et al. (ATVA'09).
498

499
500
501
502
503
504
    - GraphViz output now uses an horizontal layout by default, and
      also use circular states (unless the automaton has more than 100
      states, or uses named-states).  The --dot option of the various
      command-line tools takes an optional parameter to fine-tune the
      GraphViz output (including vertical layout, forced circular or
      elliptic states, named automata, SCC information, ordered
505
506
507
508
      transitions, and different ways to colorize the acceptance
      sets).  The environment variables SPOT_DOTDEFAULT and
      SPOT_DOTEXTRA can also be used to respectively provide a default
      argument to --dot, and add extra attributes to the output graph.
509

510
    - Never claims can now be output in the style used by Spin since
511
512
513
514
515
516
      version 6.2.4 (i.e., using do..od instead of if..fi, and with
      atomic statements for terminal acceptance).  The default output
      is still the old one for compatibility with existing tools.  The
      new style can be requested from command-line tools using option
      --spin=6 (or -s6 for short).

517
    - Support for building unambiguous automata.  ltl_to_tgba() has a
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
518
519
520
521
      new options to produce unambiguous TGBA (used by ltl2tgba -U as
      discussed above).   The function is_unambiguous() will check
      whether an automaton is unambigous, and this is used by
      autfilt --is-unmabiguous.
522

523
524
525
526
527
528
529
530
    - The SAT-based minimization algorithm for deterministic automata
      has been updated to work with ω-Automaton with any acceptance.
      The input and the output acceptance can be different, so for
      instance it is possible to create a minimal deterministic
      Streett automaton starting from a deterministic Rabin automaton.
      This functionnality is available via autfilt's --sat-minimize
      option.  See doc/userdoc/satmin.html for details.

531
532
533
    - The on-line interface at http://spot.lrde.epita.fr/trans.html
      can be used to check stutter-invariance of any LTL/PSL formula.

534
535
536
537
    - The on-line interface will work around atomic propositions not
      supported by ltl3ba.  (E.g. you can now translate F(A) or
      G("foo < bar").)

538
  * Noteworthy code changes
539
540
541

    - Boost is not used anymore.

542
543
544
545
546
547
548
549
550
551
552
553
554
    - Automata are now manipulated exclusively via shared pointers.

    - Most of what was called tgba_something is now called
      twa_something, unless it is really meant to work only for TGBA.
      This includes functions, classes, file, and directory names.
      For instance the class tgba originally defined in tgba/tgba.hh,
      has been replaced by the class twa defined in twa/twa.hh.

    - the tgba_explicit class has been completely replaced by a more
      efficient twa_graph class.  Many of the algorithms that were
      written against the abstract tgba (now twa) interface have been
      rewritten using twa_graph instances as input and output, making
      the code a lot simpler.
555

556
557
558
    - The tgba_succ_iterator (now twa_succ_iterator) interface has
      changed.  Methods next(), and first() should now return a bool
      indicating whether the current iteration is valid.
559

560
561
    - The twa base class has a new method, release_iter(), that can
      be called to give a used iterator back to its automaton.  This
562
563
564
565
      iterator is then stored in a protected member, iter_cache_, and
      all implementations of succ_iter() can be updated to recycle
      iter_cache_ (if available) instead of allocating a new iterator.

566
567
568
    - The tgba (now called twa) base class has a new method, succ(),
      to support C++11' range-based for loop, and hide all the above
      change.
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591

      Instead of the following syntax:

	tgba_succ_iterator* i = aut->succ_iter(s);
	for (i->first(); !i->done(); i->next())
	  {
	     // use i->current_state()
	     //     i->current_condition()
	     //     i->current_acceptance_conditions()
	  }
	delete i;

      We now prefer:

	for (auto i: aut->succ(s))
	  {
	    // use i->current_state()
	    //     i->current_condition()
	    //     i->current_acceptance_conditions()
	  }

      And the above syntax is really just syntactic suggar for

592
	twa_succ_iterator* i = aut->succ_iter(s);
593
594
595
596
597
598
599
600
601
602
603
604
	if (i->first())
	  do
	    {
	      // use i->current_state()
	      //     i->current_condition()
	      //     i->current_acceptance_conditions()
	    }
	  while (i->next());
	aut->release_iter(i); // allow the automaton to recycle the iterator

      Where the virtual calls to done() and delete have been avoided.

605
    - twa::succ_iter() now takes only one argument.  The optional
606
607
608
609
610
611
612
613
614
      global_state and global_automaton arguments have been removed.

    - The following methods have been removed from the TGBA interface and
      all their subclasses:
        - tgba::support_variables()
	- tgba::compute_support_variables()
	- tgba::all_acceptance_conditions()       // use acc().accepting(...)
	- tgba::neg_acceptance_conditions()
	- tgba::number_of_acceptance_conditions() // use acc().num_sets()
615

616
    - Membership to acceptance sets are now stored using bit sets,
617
      currently limited to 32 bits.  Each TωA has a acc() method that
618
619
620
621
      returns a reference to an acceptance object (of type
      spot::acc_cond), able to operate on acceptance marks
      (spot::acc_cond::mark_t).

622
      Instead of writing code like
623
624
625
        i->current_acceptance_conditions() == aut->all_acceptance_conditions()
      we now write
        aut->acc().accepting(i->current_acceptance_conditions())
626
      (Note that for accepting(x) to return something meaningful, x
627
      should be a set of acceptance sets visitied infinitely often.  So let's
628
      imagine that in the above example i is looking at a self-loop.)
629
630
631
632
633
634

      Similarly,
        aut->number_of_acceptance_conditions()
      is now
        aut->acc().num_sets()

635
636
637
638
639
640
641
642
643
644
645
    - All functions used for printing LTL/PSL formulas or automata
      have been renamed to print_something().  Likewise the various
      parsers should be called parse_something() (they haven't yet
      all been renamed).

    - All test suites under src/ have been merged into a single one in
      src/tests/.  The testing tool that was called
      src/tgbatest/ltl2tgba has been renamed as src/tests/ikwiad
      (short for "I Know What I Am Doing") so that users should be
      less tempted to use it instead of src/bin/ltl2tgba.

646
647
  * Removed features

648
    - The long unused interface to GreatSPN (or rather, interface to
649
      a non-public, customized version of GreatSPN) has been removed.
650
      As a consequence, we could get rid of many cruft in the
651
652
      implementation of Couvreur's FM'99 emptiness check.

653
654
655
656
657
658
659
660
661
662
663
    - Support for symbolic, BDD-encoded TGBAs has been removed.  This
      includes the tgba_bdd_concrete class and associated supporting
      classes, as well as the ltl_to_tgba_lacim() LTL translation
      algorithm.  Historically, this TGBA implementation and LTL
      translation were the first to be implemented in Spot (by
      mistake!) and this resulted in many bad design decisions.  In
      practice they were of no use as we only work with explicit
      automata (i.e. not symbolic) in Spot, and those produced by
      these techniques are simply too big.

    - All support for ELTL, i.e., LTL logic extended with operators
664
      represented by automata has been removed.  It was never used in
665
666
667
668
      practice because it had no practical user interface, and the
      translation was a purely-based BDD encoding producing huge
      automata (when viewed explictely), using the above and non
      longuer supported tgba_bdd_concrete class.
669

670
    - Our implementation of the Kupferman-Vardi complementation has
671
      been removed: it was unused in practice beause of the size of
672
673
674
      the automata built, and it did not survive the conversion of
      acceptance sets from BDDs to bitsets.

675
676
    - The unused implementation of state-based alternating Büchi
      automata has been removed.
677

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
678
679
680
681
682
    - Input and output in the old, Spot-specific, text format for
      TGBA, has been fully removed.  We now use HOA everywhere.  (In
      case you have a file in this format, install Spot 1.2.6 and use
      "src/tgbatest/ltl2tgba -H -X file" to convert the file to HOA.)

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
683
New in spot 1.2.6 (2014-12-06)
684

685
686
687
  * New features:

    - ltlcross --verbose is a new option to see what is being done
688

689
690
  * Bug fixes:

691
692
693
694
    - Remove one incorrect simplification rule for PSL discovered
      via checks on random formulaes.  (The bug was very unlikely
      to trigger on non-random formulas, because it requires a SERE
      with an entire subexpression that is unsatisfiable.)
695
696
697
698
699
700
    - When the automaton resulting from the translation of a positive
      formula is deterministic, ltlcross will compute its complement
      to perform additional checks against other translations of the
      positive formula.  The same procedure should be performed with
      automata obtained from negated formulas, but because of a typo
      this was not the case.
701
702
    - the neverclaim parser will now diagnose redefinitions of
      state labels.
703
704
    - the acceptance specification in the HOA format output have been
      adjusted to match recent changes in the format specifications.
705
    - atomic propositions are correctly escaped in the HOA output.
706
707
708
709
    - the build rules for documentation have been made compatible with
      version 8.0 of Org-mode.  (This was only a problem if you build
      from the git repository, or if you want to edit the
      documentation.)
710
711
712
713
    - recent to changes to libstd++ (as shipped by g++ 4.9.2) have
      demonstrated that the order of transitions output by the
      LTL->TGBA translation used to be dependent on the implementation
      of the STL.  This is now fixed.
714
715
716
717
718
    - some developpement version of libstd++ had a bug (PR 63698) in
      the assignment of std::set, and that was triggered in two places
      in Spot.  The workaround (not assigning sets) is actually more
      efficient, so we can consider it as a bug fix, even though
      libstd++ has also been fixed.
719
720
    - all parsers would report wrong line numbers while processing
      files with DOS style newlines.
721
    - add support for SWIG 3.0.
722

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
723
New in spot 1.2.5 (2014-08-21)
724

725
  * New features:
726
727
728

    - The online ltl2tgba translator will automatically attempt to
      parse a formula using LBT's syntax if it cannot parse it using
729
730
      the normal infix syntax.  It also has an option to display
      formulas using LBT's syntax.
731

732
733
734
735
736
737
    - 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.

738
739
    - 'randltl 4' is now a shorthand for 'randltl p0 p1 p2 p3'.

740
741
742
743
    - 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.

744
  * Documentation:
745
746
747
748

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

749
750
  * Bug fixes:

751
752
753
754
    - 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).
755
    - Fix simplification of bounded repetition in SERE formulas.
756
757
758
    - 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}.
759
    - Fix parsing of neverclaims produced by Modella.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
760
761
762
    - Fix a memory leak in the little-used conversion from
      transition-based alternating automata to tgba.
    - Fix a harmless uninitialized read in BuDDy.
763
764
765
766
767
    - 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.
768
769
770
771
    - '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.
772

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
773
New in spot 1.2.4 (2014-05-15)
774

775
776
777
  * New features:

    - "-B -x degen-lskip" can be used to disable level-skipping in the
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
778
779
      degeralization procedure called by ltl2tgba and dstar2tgba.
      This is mostly meant for running experiments.
780
781
782
783
784
785
    - "-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.
786
787
788
    - "ltl2tgta --ta" could crash in certain conditions due to the
      introduction of a simulation-based reduction after
      degeneralization.
789
790
791
792
793
    - 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).
794
795
    - Fix incorrect translation of the fusion operator (":") in SERE
      such as {xx;1}:yy[*] where the left operand has 1 as tail.
796

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
797
New in spot 1.2.3 (2014-02-11)
798

799
800
801
802
803
  * 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
804
      http://spot.lrde.epita.fr/satmin.html
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
805
806
    - The bench/dtgbasat/ benchmark has been updated to use SPOT_SATLOG
      and record more statistics.
807
808
809
810
    - 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.
811

812
813
814
  * Bug fixes:

    - More fixes for Python 3 compatibility.
815
816
817
    - 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).
818
819
820
821
    - 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.
822
    - Fix spurious testsuite failure when using Pandas 0.13.
823
824
825
826
827
    - 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
828
829
    - 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
830
      automaton in the next iteration...
831
832
833
834
    - 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.
835

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
836
New in spot 1.2.2 (2014-01-24)
837

838
839
840
841
842
843
844
845
  * 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
846
      when the C++ compiler is in C++11 mode.
847
848
849
850
    - 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
851
New in spot 1.2.1 (2013-12-11)
852

853
  * New features:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
854

855
856
857
858
859
860
    - 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
861

862
863
864
865
866
867
868
    - 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
869

870
871
872
    - 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
873

874
875
876
877
878
    - 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
879

880
881
882
883
    - 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
884

885
886
887
888
889
    - 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
890

891
892
    - 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
893

894
    - Please check
895
            http://spot.lrde.epita.fr/csv.html
896
      for some discussion and examples of the last few features.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
897

898
  * Bug fixes:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
899

900
901
902
903
904
905
    - 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
906

907
908
    - ltlcross failed to report missing input or output escape sequences
      on all but the first configured translator.
909

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
910
New in spot 1.2 (2013-10-01)
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
911

912
913
914
915
916
917
918
919
  * 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.
920

921
922
    - ltlcross can now read the Rabin and Streett automata output by
      ltl2dstar.  This type of output should be specified using '%D':
923

924
        ltlcross 'ltl2dstar --ltl2nba=spin:path/to/ltl2tgba@-s %L %D'
925

926
      However because Spot only supports Büchi acceptance, these Rabin
927
      and Streett automata are immediately converted to TGBAs before
928
929
      further processing by ltlcross.  This is still interesting to
      search for bugs in translators to Rabin or Streett automata, but
930
      the statistics (of the resulting TGBAs) might not be very relevant.
931

932
933
934
935
936
937
    - 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.

938
939
940
941
    - 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.
942

943
    - There is a new command, named dstar2tgba, that converts a
944
945
946
947
948
949
950
951
952
953
954
955
      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.
956

957
      See http://spot.lrde.epita.fr/dstar2tgba.html for some
958
959
      examples, and the man page for more reference.

960
961
962
963
964
    - 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.

965
      Additionally, the %p escape can now be used to show whether the
966
967
968
      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).
969

970
971
972
973
974
    - 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
975
976
      properties that are stronger than obligations (for obligations
      our WDBA-minimization procedure will return a minimimal
977
978
979
      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.
980
      See also http://spot.lrde.epita.fr/satmin.html for some
981
      examples.
982

983
984
985
986
    - 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.
987

988
989
990
991
    - ltlfilt, genltl, and randltl have a new --format option to
      indicate how to present the output formula, possibly with
      information about the input.

992
993
994
995
996
    - 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".

997
  * New functions and classes in the library:
998

999
1000
    - dtba_sat_synthetize(): Use a SAT-solver to build an equivalent
      deterministic TBA with a fixed number of states.
1001

1002
1003
    - dtba_sat_minimize(), dtba_sat_minimize_dichotomy(): Iterate
      dtba_sat_synthetize() to reduce the number of states of a TBA.
1004

1005
1006
    - dtgba_sat_synthetize(), dtgba_sat_minimize(),
      dtgba_sat_minimize_dichotomy(): Likewise, for deterministic TGBA.
1007

1008
    - is_complete(): Check whether a TGBA is complete.
1009

1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
    - 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.

1058
1059
    - to_latex_string(): Output a formula using LaTeX syntax.

1060
1061
1062
    - relabel_bse(): Relabeling of Boolean Sub-Expressions.
      Implements ltlfilt's --relabel-bool option describe above.

1063
1064
1065
1066
1067
  * 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
1068
1069
      using dtgba_complement().  This allows dstar2tgba to apply
      WDBA-minimization on deterministic Rabin automata.
1070
1071
1072

    - 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
1073
      inherit from tgba_reachable_iterator anymore.
1074

1075
1076
1077
1078
    - 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.

1079
1080
1081
1082
1083
    - 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
1084
1085
1086
1087
    - 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).

1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
    - 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.
1119

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1120

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1121
New in spot 1.1.4 (2013-07-29)
1122

1123
1124
1125
1126
1127
  * 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
1128
1129
      parse further neverclaims after the first failure.
    - Add a missing newline in some error message of ltlcross.
1130
1131
1132
1133
1134
1135
1136
    - 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
1137
    - Various typos.
1138

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1139
New in spot 1.1.3 (2013-07-09)
1140

1141
1142
1143
1144
1145
1146
1147
1148
  * 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.
1149
    - A memory corruption in ltlcross.
1150

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1151
New in spot 1.1.2 (2013-06-09)
1152

1153
1154
1155
1156
1157
  * 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.
1158

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1159
New in spot 1.1.1 (2013-05-13):
1160

1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
  * 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).

1185
1186
1187
1188
1189
1190
    - 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.

1191
1192
1193
1194
1195
1196
1197
1198
1199
    - 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.

1200
1201
1202
    - ltlcross has a new option --seed, that makes it possible to
      change the seed used by the random graph generator.

1203
1204
1205
1206
1207
1208
1209
1210
    - 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.

1211
1212
1213
1214
    - 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.

1215
  * Bug fixes:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1216
1217

    - genltl --gh-r generated the wrong formulas due to a typo.
1218
1219
    - ltlfilt --eventual and --universal were not handled properly.
    - ltlfilt --stutter-invariant would trigger an assert on PSL formulas.
1220
1221
    - ltl2tgba, ltl2tgta, ltlcross, and ltlfilt, would all choke on empty
      lines in a file of formulas.  They now ignore empty lines.
1222
1223
1224
1225
1226
1227
1228
1229
    - 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.
1230

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1231
New in spot 1.1 (2013-04-28):
1232

1233
1234
1235
1236
1237
1238
1239
  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.

1240
  * New features in the library:
1241

1242
1243
1244
    - 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
1245
1246
      postprocessings.

1247
1248
1249
1250
1251
1252
    - 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.

1253
1254
1255
1256
    - 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
1257
      disabled by default.  (See SPIN'13 paper.)
1258
1259
1260
1261

    - 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
1262
      simplified previously.  (See SPIN'13 paper.)
1263

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1264
1265
1266
1267
1268
1269
1270
1271
1272
    - 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.

1273
1274
1275
1276
1277
    - 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.

1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
    - 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.

1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
    - 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.

1302
  * Command-line tools:
1303
1304

    - ltl2tgba and ltl2tgta now honor a new --extra-options (or -x)
1305
1306
1307
      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.
1308

1309
1310
1311
1312
1313
1314
    - 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).

1315
1316
1317
1318
    - 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.

1319
  * Documentation:
1320
1321

    - org-mode files used to generate the documentation about
1322
      command-line tools (shown at http://spot.lrde.epita.fr/tools.html)
1323
1324
1325
      is distributed in doc/org/.  The resulting html files are also
      in doc/userdoc/.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
  * 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.

1336
1337
  * Bug fixes:

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1338
1339
    - There was a memory leak in the LTL simplification code, that could
      only be triggered when disabling advanced simplifications.
1340

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1341
1342
    - The translation of the PSL formula !{xxx} was incorrect when xxx
      simplified to false.
1343

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1344
    - Various warnings triggered by new compilers.
1345

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1346
New in spot 1.0.2 (2013-03-06):
1347

1348
1349
1350
1351
  * 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.
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
    - 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.
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378