NEWS 98.8 KB
Newer Older
1
2
New in spot 1.99.4a (not yet released)

3
4
5
6
7
8
9
  Command-line tools:

  * autfilt has gained a --complement option.
    It currently work only for deterministic automata.

  Library:

10
11
12
13
14
15
16
17
18
19
  * Rename dtgba_complement() as dtwa_complement(), rename the header
    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().

20
21
22
23
24
25
26
27
  * 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.)

28
29
  Python:

30
  * Add bindings for complete() and dtwa_complement()
31
32
  * Formulas now have a custom __format__ function.  See
    https://spot.lrde.epita.fr/tut01.html for examples.
33
34
35
36
37
38
39
40
41

  Bugs fixed:

  * Work around some strange weird exception raised when using the
    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.
42
  * "randaut -Q0 1" used to segfault.
43

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
44
New in spot 1.99.4 (2015-10-01)
45

46
47
  New features:

48
49
50
51
  * 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.
52

53
54
55
56
57
58
59
60
61
62
  * 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.

63
64
65
66
67
68
69
70
71
72
  * 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.)

73
74
  Major code changes and reorganization:

75
76
77
  * 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
78
    - LTL/PSL formulas are now represented by lightweight formula
79
80
81
82
      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
83
      used to distinguish between operators.
84
85
86
87
88
89
90
91
    - 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.
92

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
93
94
95
96
97
  * 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.

98
99
100
  * The LTL/PSL parser is now declared in tl/parse.hh (instead of
    ltlparse/public.hh).

101
102
103
104
105
106
107
108
109
110
111
  * 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.
112

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
113
New in spot 1.99.3 (2015-08-26)
114

115
116
117
  * The CGI script for LTL translation offers a HOA download link
    for each generated automaton.

118
  * The html documentation now includes a HTML copies of the man
119
    pages, and HTML copies of the Python notebooks.
120

121
122
123
124
  * scc_filter(aut, true) does not remove Fin marks from rejecting
    SCCs, but it now does remove Fin marks from transitions between
    SCCs.

125
126
127
  * All the unabbreviation functions (unabbreviate_ltl(),
    unabbreviate_logic(), unabbreviate_wm()) have been merged into a
    single unabbreviate() function that takes a string representing
128
129
130
    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.
131

132
133
134
135
  * 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.)

136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
  * 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
159
      converting them to Büchi.
160
161
    - 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
162
      automata.  This implies a few minor semantic changes, for
163
      instance --stats=%A used to output the number of acceptance
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
164
      *pairs* in the input automaton, while it now outputs the
165
166
      number of acceptance sets like in all the other tools.

167
168
  * Bugs fixed
    - Some acceptance conditions like Fin(0)|Fin(1)|Fin(2)&Inf(3)
169
      were not detected as generalized-Rabin.
170
171
    - 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
172
    - The CGI script for LTL translation now forces transition-based
173
174
175
176
      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
177
178
    - 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
179
180
      slightly wrong.  For instance ^ was incorrectly escaped, and
      the double quotes where not always properly rendered.
181
182
    - A spurious assertion was triggered by streett_to_generalized_buchi(),
      but only when compiled in DEBUG mode.
183
    - LTL formula rewritten in Spin's syntax no longer have their ->
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
184
      and <-> rewritten away.
185
    - Fix some warnings reported by the development version of GCC 6.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
186
    - The spot.translate() function of the Python binding had a typo
187
      preventing the use of 'low'/'medium'/'high' as argument.
188
    - Fix spurious failure of uniq.test under different locales.
189
190
    - ltlcross now recovers from out-of-memory errors during
      state-space products.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
191
192
    - bitvect.test was failing on 32bit architectures with
      assertions enabled because of a bug in the test case.
193

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
194
New in spot 1.99.2 (2015-07-18)
195

196
  * The scc_info object, used to build a map of SCCs while gathering
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
197
    additional information, has been simplified and speed up.  One
198
    test case where ltlcross would take more than 13min (to check the
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
199
    translation of one PSL formula) now takes only 75s.
200

201
202
203
  * 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
204
    remove_fin() functions when the input automaton is a Streett
205
206
207
208
209
210
211
212
213
    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
214
215
216
217
    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.
218

219
  * Bugs fixed:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
220
    - p[+][:*2] was not detected as belonging to siPSL.
221
222
    - scc_filter() would incorrectly remove Fin marks from
      rejecting SCCs.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
223
    - the libspotltsmin library is installed.
224
    - ltlcross and ltldo did not properly quote atomic propositions
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
225
226
      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
227
228
229
230
      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.
231

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
232
New in spot 1.99.1 (2015-06-23)
233

234
235
236
237
238
  * 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
239
      Automata) while this version now deals with what we call TωA
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
      (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.

259
    - As a consequence of the switches to C++11 and to TωA, a lot of
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
      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
293
      have a tool that is bogus on some formula that is too large to
294
295
296
      debug, you can use ltlgrind to generate smaller derived formulas
      and see if you can reproduce the bug on those.

297
298
299
300
301
302
303
304
305
306
307
308
      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
309
    - ltl2tgba has a new option, -U, to produce unambiguous automata.
310
311
312
      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
313

314
    - ltl2tgba has a new option, -S, to produce generalized-Büchi
315
316
317
318
319
      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.

320
321
322
323
324
    - 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.

325
    - ltlcross has several new options:
326

327
328
        --grind attempts to reduce the size of any bogus formula it
        discovers, while still exhibiting the bug.
329

330
331
        --ignore-execution-failures ignores cases where a translator
        exits with a non-zero status.
332
333

	--automata save the produced automata into the CSV or JSON
334
        file.  Those automata are saved using the HOA format.
335
336
337
338
339

      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.
340

341
    - "ltlfilt --stutter-invariant" will now work with PSL formulas.
342
      The implementation is actually much more efficient
343
      than our previous implementation that was only for LTL.
344

345
346
347
348
349
    - 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.

350
351
352
353
    - 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.

354
355
356
    - ltlfilt has a new --count option to count the number of matching
      automata.

357
358
359
    - ltlfilt has a new --exclusive-ap option to constrain formulas
      based on a list of mutually exclusive atomic propositions.

360
361
362
363
    - 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.

364
365
366
367
368
369
    - 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.

370
371
372
373
    - 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
374
375
376
377
378
379
380
381
382
383
      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
384
385
      or 'stutter-sensitive'.  Another check performed by
      --check is testing whether the automaton is unambiguous.
386

387
388
389
390
391
392
    - 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.

393
394
    - For options that take an output filename (i.e., ltlcross's
      --save-bogus, --grind, --csv, --json) you can force the file
395
396
      to be opened in append mode (instead of being truncated) by
      by prefixing the filename with ">>".  For instance
397
398
399
      	  --save-bogus=">>bugs.ltl"
      will append to the end of the file.

400
401
  * Other noteworthy news

402
403
404
405
406
407
408
409
    - 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.)

410
411
412
413
    - 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.

414
415
    - There is a parser for the HOA format
      (http://adl.github.io/hoaf/) available as a
416
417
418
419
420
421
      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
422
423
      alternation.  Multiple initial states are converted into an
      extra initial state; complemented acceptance sets Inf(!x) are
424
425
      converted to Inf(x); explicit or implicit labels can be used;
      aliases are supported; "--ABORT--" can be used in a stream.
426

427
428
429
430
431
432
    - 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).
433

434
435
    - While not all algorithms in the library are able to work with
      any acceptance condition supported by the HOA format, the
436
      following two new functions mitigate that:
437
438
439
440
441
442
443
444
445
446

      - 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.

447
448
449
    - 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
450

451
452
    - the interface in iface/dve2 has been renamed to iface/ltsmin
      because it can now interface the dynamic libraries created
453
      either by Divine (as patched by the LTSmin group) or by
454
455
      Spins (the LTSmin compiler for Promela).

456
457
458
459
460
461
462
463
    - 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).
464

465
466
467
468
469
470
    - 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
471
472
473
474
      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.
475

476
    - Never claims can now be output in the style used by Spin since
477
478
479
480
481
482
      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).

483
    - Support for building unambiguous automata.  ltl_to_tgba() has a
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
484
485
486
487
      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.
488

489
490
491
492
493
494
495
496
    - 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.

497
498
499
    - The on-line interface at http://spot.lrde.epita.fr/trans.html
      can be used to check stutter-invariance of any LTL/PSL formula.

500
501
502
503
    - 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").)

504
  * Noteworthy code changes
505
506
507

    - Boost is not used anymore.

508
509
510
511
512
513
514
515
516
517
518
519
520
    - 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.
521

522
523
524
    - 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.
525

526
527
    - The twa base class has a new method, release_iter(), that can
      be called to give a used iterator back to its automaton.  This
528
529
530
531
      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.

532
533
534
    - 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.
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557

      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

558
	twa_succ_iterator* i = aut->succ_iter(s);
559
560
561
562
563
564
565
566
567
568
569
570
	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.

571
    - twa::succ_iter() now takes only one argument.  The optional
572
573
574
575
576
577
578
579
580
      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()
581

582
    - Membership to acceptance sets are now stored using bit sets,
583
      currently limited to 32 bits.  Each TωA has a acc() method that
584
585
586
587
      returns a reference to an acceptance object (of type
      spot::acc_cond), able to operate on acceptance marks
      (spot::acc_cond::mark_t).

588
      Instead of writing code like
589
590
591
        i->current_acceptance_conditions() == aut->all_acceptance_conditions()
      we now write
        aut->acc().accepting(i->current_acceptance_conditions())
592
      (Note that for accepting(x) to return something meaningful, x
593
      should be a set of acceptance sets visitied infinitely often.  So let's
594
      imagine that in the above example i is looking at a self-loop.)
595
596
597
598
599
600

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

601
602
603
604
605
606
607
608
609
610
611
    - 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.

612
613
  * Removed features

614
    - The long unused interface to GreatSPN (or rather, interface to
615
      a non-public, customized version of GreatSPN) has been removed.
616
      As a consequence, we could get rid of many cruft in the
617
618
      implementation of Couvreur's FM'99 emptiness check.

619
620
621
622
623
624
625
626
627
628
629
    - 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
630
      represented by automata has been removed.  It was never used in
631
632
633
634
      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.
635

636
    - Our implementation of the Kupferman-Vardi complementation has
637
      been removed: it was unused in practice beause of the size of
638
639
640
      the automata built, and it did not survive the conversion of
      acceptance sets from BDDs to bitsets.

641
642
    - The unused implementation of state-based alternating Büchi
      automata has been removed.
643

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
644
645
646
647
648
    - 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
649
New in spot 1.2.6 (2014-12-06)
650

651
652
653
  * New features:

    - ltlcross --verbose is a new option to see what is being done
654

655
656
  * Bug fixes:

657
658
659
660
    - 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.)
661
662
663
664
665
666
    - 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.
667
668
    - the neverclaim parser will now diagnose redefinitions of
      state labels.
669
670
    - the acceptance specification in the HOA format output have been
      adjusted to match recent changes in the format specifications.
671
    - atomic propositions are correctly escaped in the HOA output.
672
673
674
675
    - 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.)
676
677
678
679
    - 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.
680
681
682
683
684
    - 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.
685
686
    - all parsers would report wrong line numbers while processing
      files with DOS style newlines.
687
    - add support for SWIG 3.0.
688

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
689
New in spot 1.2.5 (2014-08-21)
690

691
  * New features:
692
693
694

    - The online ltl2tgba translator will automatically attempt to
      parse a formula using LBT's syntax if it cannot parse it using
695
696
      the normal infix syntax.  It also has an option to display
      formulas using LBT's syntax.
697

698
699
700
701
702
703
    - 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.

704
705
    - 'randltl 4' is now a shorthand for 'randltl p0 p1 p2 p3'.

706
707
708
709
    - 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.

710
  * Documentation:
711
712
713
714

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

715
716
  * Bug fixes:

717
718
719
720
    - 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).
721
    - Fix simplification of bounded repetition in SERE formulas.
722
723
724
    - 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}.
725
    - Fix parsing of neverclaims produced by Modella.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
726
727
728
    - Fix a memory leak in the little-used conversion from
      transition-based alternating automata to tgba.
    - Fix a harmless uninitialized read in BuDDy.
729
730
731
732
733
    - 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.
734
735
736
737
    - '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.
738

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
739
New in spot 1.2.4 (2014-05-15)
740

741
742
743
  * New features:

    - "-B -x degen-lskip" can be used to disable level-skipping in the
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
744
745
      degeralization procedure called by ltl2tgba and dstar2tgba.
      This is mostly meant for running experiments.
746
747
748
749
750
751
    - "-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.
752
753
754
    - "ltl2tgta --ta" could crash in certain conditions due to the
      introduction of a simulation-based reduction after
      degeneralization.
755
756
757
758
759
    - 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).
760
761
    - Fix incorrect translation of the fusion operator (":") in SERE
      such as {xx;1}:yy[*] where the left operand has 1 as tail.
762

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
763
New in spot 1.2.3 (2014-02-11)
764

765
766
767
768
769
  * 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
770
      http://spot.lrde.epita.fr/satmin.html
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
771
772
    - The bench/dtgbasat/ benchmark has been updated to use SPOT_SATLOG
      and record more statistics.
773
774
775
776
    - 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.
777

778
779
780
  * Bug fixes:

    - More fixes for Python 3 compatibility.
781
782
783
    - 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).
784
785
786
787
    - 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.
788
    - Fix spurious testsuite failure when using Pandas 0.13.
789
790
791
792
793
    - 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
794
795
    - 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
796
      automaton in the next iteration...
797
798
799
800
    - 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.
801

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
802
New in spot 1.2.2 (2014-01-24)
803

804
805
806
807
808
809
810
811
  * 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
812
      when the C++ compiler is in C++11 mode.
813
814
815
816
    - 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
817
New in spot 1.2.1 (2013-12-11)
818

819
  * New features:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
820

821
822
823
824
825
826
    - 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
827

828
829
830
831
832
833
834
    - 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
835

836
837
838
    - 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
839

840
841
842
843
844
    - 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
845

846
847
848
849
    - 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
850

851
852
853
854
855
    - 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
856

857
858
    - 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
859

860
    - Please check
861
            http://spot.lrde.epita.fr/csv.html
862
      for some discussion and examples of the last few features.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
863

864
  * Bug fixes:
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
865

866
867
868
869
870
871
    - 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
872

873
874
    - ltlcross failed to report missing input or output escape sequences
      on all but the first configured translator.
875

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
876
New in spot 1.2 (2013-10-01)
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
877

878
879
880
881
882
883
884
885
  * 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.
886

887
888
    - ltlcross can now read the Rabin and Streett automata output by
      ltl2dstar.  This type of output should be specified using '%D':
889

890
        ltlcross 'ltl2dstar --ltl2nba=spin:path/to/ltl2tgba@-s %L %D'
891

892
      However because Spot only supports Büchi acceptance, these Rabin
893
      and Streett automata are immediately converted to TGBAs before
894
895
      further processing by ltlcross.  This is still interesting to
      search for bugs in translators to Rabin or Streett automata, but
896
      the statistics (of the resulting TGBAs) might not be very relevant.
897

898
899
900
901
902
903
    - 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.

904
905
906
907
    - 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.
908

909
    - There is a new command, named dstar2tgba, that converts a
910
911
912
913
914
915
916
917
918
919
920
921
      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.
922

923
      See http://spot.lrde.epita.fr/dstar2tgba.html for some
924
925
      examples, and the man page for more reference.

926
927
928
929
930
    - 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.

931
      Additionally, the %p escape can now be used to show whether the
932
933
934
      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).
935

936
937
938
939
940
    - 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
941
942
      properties that are stronger than obligations (for obligations
      our WDBA-minimization procedure will return a minimimal
943
944
945
      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.
946
      See also http://spot.lrde.epita.fr/satmin.html for some
947
      examples.
948

949
950
951
952
    - 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.
953

954
955
956
957
    - ltlfilt, genltl, and randltl have a new --format option to
      indicate how to present the output formula, possibly with
      information about the input.

958
959
960
961
962
    - 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".

963
  * New functions and classes in the library:
964

965
966
    - dtba_sat_synthetize(): Use a SAT-solver to build an equivalent
      deterministic TBA with a fixed number of states.
967

968
969
    - dtba_sat_minimize(), dtba_sat_minimize_dichotomy(): Iterate
      dtba_sat_synthetize() to reduce the number of states of a TBA.
970

971
972
    - dtgba_sat_synthetize(), dtgba_sat_minimize(),
      dtgba_sat_minimize_dichotomy(): Likewise, for deterministic TGBA.
973

974
    - is_complete(): Check whether a TGBA is complete.
975

976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
    - 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()
For faster browsing, not all history is shown. View entire blame