NEWS 185 KB
Newer Older
1
2
New in spot 2.5.1.dev (not yet released)

3
4
5
6
7
  Bugs fixed:

  - acc_cond::is_generalized_rabin() and
    acc_cond::is_generalized_streett() would segfault on weird
    acceptance conditions such as "3 t" or "3 f".
8

9
10
11
  - remove_fin(), streett_to_generalized_buchi() should never
    return automata with "f" acceptance.

12
13
14
  - "autfilt --acceptance-is=Fin-less" no longer accept automata
    with "f" acceptance.

15
16
17
  - twa_run methods will now diagnose cases where the cycle is
    unexpectedly empty instead of segfaulting.

18
19
20
21
22
23
24
25
  - spot::closure(), used by default for testing stutter-invariance,
    was using an optimization incorrect if the acceptance condition
    had some Fin(x).  Consequently stutter-invariance tests for
    automata, for instance with "autfilt --is-stutter-invariant",
    could be to be wrong (even if the input does not use Fin(x), its
    complement, used in the stutter-invariance test likely will).
    Stutter-invariance checks of LTL formulas are not affected.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
26
New in spot 2.5.1 (2018-02-20)
27

Maximilien Colange's avatar
Maximilien Colange committed
28
29
30
31
  Library:

  - iar() and iar_maybe() now also handle Streett-like conditions.

32
33
  Bugs fixed:

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
34
35
  - iar() and iar_maybe() properly handle Rabin-like conditions.

36
37
38
  - streett_to_generalized_buchi() could produce incorrect result on
    Streett-like input with acceptance like (Inf(0)|Fin(1))&Fin(1)
    where some Fin(x) is used both with and without a paired Fin(y).
39

40
41
42
43
44
45
  - is_generalized_rabin() had a typo that caused some non-simplified
    acceptance conditions like Fin(0)|(Fin(0)&Inf(1)) to be
    incorrectly detecteded as generalized-Rabin 2 0 1 and then output
    as Fin(0)|(Fin(1)&Inf(2)) instead.  Likewise for
    is_generalized_streett

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
46
47
48
49
  - the conversion from Rabin to Büchi was broken on Rabin-like
    acceptance condition where one pair used Fin(x) and another pair
    used Inf(x) with the same x.  Unfortunately, this situation could
    also occur as a side effect of simplifying the acceptance
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
50
51
    condition (by merging identical set) of some automaton prior to
    converting it to Büchi.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
52

53
54
  - dnf_to_dca() was mishandling some Rabin-like input.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
55
New in spot 2.5 (2018-01-20)
56

57
58
  Build:

Maximilien Colange's avatar
Maximilien Colange committed
59
  - We no longer distribute the doxygen-generated documentation in
60
61
62
63
64
    the tarball of Spot to save space.  This documentation is still
    available online at https://spot.lrde.epita.fr/doxygen/.  If you
    want to build a local copy you can configure Spot with
    --enable-doxygen, or simply run "cd doc && make doc".

65
66
67
  - All the images that illustrate the documentation have been
    converted to SVG, to save space and improve quality.

68
69
  Tools:

70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
  - ltlsynt is a new tool for synthesizing a controller from LTL/PSL
    specifications.

  - ltlcross learned --reference=COMMANDFMT to specify a translator
    that should be trusted.  Doing so makes it possible to reduce the
    number of tests to be performed, as all other translators will be
    compared to the reference's output when available.  Multiple
    reference can be given; in that case other tools are compared
    against the smallest reference automaton.

  - autcross, ltlcross, and ltldo learned --fail-on-timeout.

  - ltl2tgba, autfilt, and dstar2tgba have some new '--parity' and
    '--colored-parity' options to force parity acceptance on the
    output.  Different styles can be requested using for instance
    --parity='min odd' or --parity='max even'.

87
88
89
  - ltl2tgba, autfilt, and dstar2tgba have some new '--cobuchi' option
    to force co-Büchi acceptance on the output.  Beware: if the input
    language is not co-Büchi realizable the output automaton will
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
90
91
    recognize a superset of the input.  Currently, the output is
    always state-based.
92

93
94
95
  - genltl learned to generate six new families of formulas, taken from
    the SYNTCOMP competition on reactive synthesis, and from from
    Müller & Sickert's GandALF'17 paper:
96
97
    --gf-equiv=RANGE       (GFa1 & GFa2 & ... & GFan) <-> GFz
    --gf-implies=RANGE     (GFa1 & GFa2 & ... & GFan) -> GFz
98
99
100
101
    --ms-example=RANGE     GF(a1&X(a2&X(a3&...)))&F(b1&F(b2&F(b3&...)))
    --ms-phi-h=RANGE       FG(a|b)|FG(!a|Xb)|FG(a|XXb)|FG(!a|XXXb)|...
    --ms-phi-r=RANGE       (FGa{n}&GFb{n})|((FGa{n-1}|GFb{n-1})&(...))
    --ms-phi-s=RANGE       (FGa{n}|GFb{n})&((FGa{n-1}&GFb{n-1})|(...))
102

103
104
  - autfilt learned --streett-like to convert automata with DNF
    acceptance into automata with Streett-like acceptance.
105

106
107
108
109
110
  - autfilt learned --acceptance-is=ACC to filter automata by
    acceptance condition.  ACC can be the name of some acceptance
    class (e.g. Büchi, Fin-less, Streett-like) or a precise acceptance
    formula in the HOA syntax.

111
112
  - ltldo learned to limit the number of automata it outputs using -n.

113
114
  - ltlfilt learned to measure wall-time using --format=%r, and
    cpu-time with --format=%R.
115

116
117
  - The --format=%g option of tools that output automata used to
    print the acceptance condition as a *formula* in the HOA format.
118
    This %g may now take optional arguments to print the acceptance
119
120
121
122
123
124
125
126
    *name* in different formats.  For instance

       ... | autfilt -o '%[s]g.hoa'

    will separate a stream of automata into different files named
    by their acceptance name (Buchi, co-Buchi, Streett, etc.) or
    "other" if no name is known for the acceptance condition.

127
128
129
  - Tools that produce formulas now support --format=%[OP]n to
    display the nesting depth of operator OP.

130
131
  - The new -x tls-impl=N option allows to fine-tune the
    implication-based simplification rules of ltl2tgba.  See the
Maximilien Colange's avatar
Maximilien Colange committed
132
    spot-x(7) man page for details.
133

134
135
  - All tools learned to check the SPOT_OOM_ABORT environment
    variable.  This is only useful for debuging out-of-memory
Maximilien Colange's avatar
Maximilien Colange committed
136
    conditions. See the spot-x(7) man page for details.
137

138
139
  New functions in the library:

140
  - spot::iar() and spot::iar_maybe() use index appearance records (IAR)
Maximilien Colange's avatar
Maximilien Colange committed
141
    to translate Rabin-like automata into equivalent parity automata.
142
143
144
    This translation preserves determinism and is especially useful when
    the input automaton is deterministic.

145
146
147
148
149
150
151
152
153
154
155
  - spot::print_aiger() encodes an automaton as an AIGER circuit, as
    required by the SYNTCOMP competition.  It relies on a new named
    property "synthesis outputs" that describes which atomic
    propositions are to be encoded as outputs of the circuits.

  - spot::dnf_to_streett() converts any automaton with a DNF
    acceptance condition into a Streett-like automaton.

  - spot::nsa_to_nca(), spot::dfn_to_nca(), spot::dfn_to_dca(), and
    spot::nsa_to_dca(), convert automata with DNF or Streett-like
    acceptance into deterministic or non-deterministic co-Büchi
Maximilien Colange's avatar
Maximilien Colange committed
156
157
    automata.  spot::to_dca() and spot::to_nca() dispatch between
    these four functions.  The language of produced automaton includes
158
159
    the original language, but may be larger if the original automaton
    is not co-Büchi realizable.  Based on Boker & Kupferman FOSSACS'11
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
160
    paper.  Currently only supports state-based output.
161

Maximilien Colange's avatar
Maximilien Colange committed
162
  - spot::scc_info::states_on_acc_cycle_of() returns all states
163
164
165
166
167
168
169
170
171
172
    visited by any accepting cycle of the specified SCC.  It only
    works on automata with Streett-like acceptance.

  - spot::is_recurrence(), spot::is_persistence(), and
    spot::is_obligation() test if a formula is a recurrence,
    persistance or obligation.  The SPOT_PR_CHECK and SPOT_O_CHECK
    environment variables can be used to select between multiple
    implementations of these functions (see the spot-x(7) man page).

  - spot::is_colored() checks if an automaton is colored
Maximilien Colange's avatar
Maximilien Colange committed
173
    (i.e., every transition belongs to exactly one acceptance set).
174

Maximilien Colange's avatar
Maximilien Colange committed
175
  - spot::change_parity() converts between different parity acceptance
176
    conditions.
177

Maximilien Colange's avatar
Maximilien Colange committed
178
  - spot::colorize_parity() transforms an automaton with parity
179
180
    acceptance into a colored automaton (which is often what people
    working with parity automata expect).
181

Maximilien Colange's avatar
Maximilien Colange committed
182
  - spot::cleanup_parity_acceptance() simplifies a parity acceptance
183
    condition.
184

185
186
187
  - spot::parity_product() and spot::parity_product_or() are
    specialized (but expensive) products that preserve parity
    acceptance.
188

189
190
191
  - spot::remove_univ_otf() removes universal transitions on the fly
    from an alternating Büchi automaton using Miyano and Hayashi's
    breakpoint algorithm.
192

193
194
  - spot::stutter_invariant_states(),
    spot::stutter_invariant_letters(),
Maximilien Colange's avatar
Maximilien Colange committed
195
    spot::highlight_stutter_invariant_states(), ...  These functions
196
197
    help study a stutter-sensitive automaton and detect the subset of
    states that are stutter-invariant.  See
198
    https://spot.lrde.epita.fr/ipynb/stutter-inv.html for examples.
199

200
  - spot::acc_cond::name(fmt) is a new method that names well-known
Maximilien Colange's avatar
Maximilien Colange committed
201
    acceptance conditions.  The fmt parameter specifies the format to
202
203
    use for that name (e.g. to the style used in HOA, or that used by
    print_dot()).
204

205
206
  - spot::formula::is_leaf() method can be used to detect formulas
    without children (atomic propositions, or constants).
207

208
209
  - spot::nesting_depth() computes the nesting depth of any LTL
    operator.
210

211
212
  - spot::check_determinism() sets both prop_semi_deterministic()
    and prop_universal() appropriately.
213

214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
  Improvements to existing functions in the library:

  - spot::tgba_determinize() has been heavily rewritten and
    optimized. The algorithm has (almost) not changed, but it is
    much faster now. It also features an optimization for
    stutter-invariant automata that may produce slightly smaller
    automata.

  - spot::scc_info now takes an optional argument to disable some
    features that are expensive and not always necessary.  By
    default scc_info tracks the list of all states that belong to an
    SCC (you may now ask it not to), tracks the successor SCCs of
    each SCC (that can but turned off), and explores all SCCs of the
    automaton (you may request to stop on the first SCC that is
    found accepting).

  - In some cases, spot::degeneralize() would output Büchi automata
    with more SCCs than its input.  This was hard to notice, because
    very often simulation-based simplifications remove those extra
    SCCs.  This situation is now detected by spot::degeneralized()
Maximilien Colange's avatar
Maximilien Colange committed
234
    and fixed before returning the automaton.  A new optional
235
236
237
238
239
240
241
242
243
244
245
246
247
    argument can be passed to disable this behavior (or use -x
    degen-remscc=0 from the command-line).

  - The functions for detecting stutter-invariant formulas or
    automata have been overhauled.  Their interface changed
    slightly.  They are now fully documented.

  - spot::postprocessor::set_type() can now request different forms
    of parity acceptance as output.  However currently the
    conversions are not very smart: if the input does not already
    have parity acceptance, it will simply be degeneralized or
    determinized.

248
249
250
251
  - spot::postprocessor::set_type() can now request co-Büchi
    acceptance as output.  This calls the aforementioned to_nca() or
    to_dca() functions.

252
253
254
255
256
257
258
  - spot::remove_fin() will now call simplify_acceptance(),
    introduced in 2.4, before attempting its different Fin-removal
    strategies.

  - spot::simplify_acceptance() was already merging identical
    acceptance sets, and detecting complementary sets i and j to
    perform the following simplifications
259
260
261
262
263
264
265
      Fin(i) & Inf(j) = Fin(i)
      Fin(i) | Inf(j) = Inf(i)
    It now additionally applies the following rules (again assuming i
    and j are complementary):
      Fin(i) & Fin(j) = f          Inf(i) | Inf(j) = t
      Fin(i) & Inf(i) = f          Fin(i) | Inf(i) = t

266
267
268
269
  - spot::formula::map(fun) and spot::formula::traverse(fun) will
    accept additionnal arguments and pass them to fun().  See
    https://spot.lrde.epita.fr/tut03.html for some examples.

270
  Python-specific changes:
271
272

  - The "product-states" property of automata is now accessible via
273
    spot.twa.get_product_states() and spot.twa.set_product_states().
274

275
276
277
278
  - twa_word instances can be displayed as SVG pictures, with one
    signal per atomic proposition.  For some examples, see the use of
    the show() method in https://spot.lrde.epita.fr/ipynb/word.html

279
280
  - The test suite is now using v4 of the Jupyter Notebook format.

281
282
283
284
  - The function rabin_is_buchi_realizable() as its name suggests checks
    if a rabin aut. is Büchi realizable. It is heavily based on
    tra_to_tba() algorithm.

285
286
287
288
289
  Deprecation notices:

  (These functions still work but compilers emit warnings.)

  - spot::scc_info::used_acc(), spot::scc_info::used_acc_of() and
290
    spot::scc_info::acc() are deprecated.  They have been renamed
291
    spot::scc_info::marks(), spot::scc_info::marks_of() and
292
    spot::scc_info::acc_sets_of() respectively for clarity.
293

294
295
296
  Backward incompatible changes:

  - The spot::closure(), spot::sl2(), spot::is_stutter_invariant()
Maximilien Colange's avatar
Maximilien Colange committed
297
    functions no longer take && arguments.  The former two have
298
299
    spot::closure_inplace() and spot::sl2_inplace() variants.  These
    functions also do not take a list of atomic propositions as an
300
301
    argument anymore.

302
  - The spot::bmrand() and spot::prand() functions have been removed.
Maximilien Colange's avatar
Maximilien Colange committed
303
    They were not used at all in Spot, and it is not Spot's objective
304
305
    to provide such random functions.

306
  - The spot::bdd_dict::register_all_propositions_of() function has
Maximilien Colange's avatar
Maximilien Colange committed
307
    been removed.  This low-level function was not used anywhere in
308
309
    Spot anymore, since it's better to use spot::twa::copy_ap_of().

310
311
  Bugs fixed:

312
313
314
315
  - spot::simplify_acceptance() could produce incorrect output if the
    first edge of the automaton was the only one with no acceptance
    set.  In spot 2.4.x this function was only used by autfilt
    --simplify-acceptance; in 2.5 it is now used in remove_fin().
316

317
318
319
320
  - spot::streett_to_generalized_buchi() could generate incorrect
    automata with empty language if some Fin set did not intersect all
    accepting SCCs (in other words, the fix from 2.4.1 was incorrect).

321
  - ltlcross could crash when calling remove_fin() on an automaton
Maximilien Colange's avatar
Maximilien Colange committed
322
    with 32 acceptance sets that would need an additional set.
323

324
325
326
327
  - the down_cast() helper function used in severaly headers of Spot
    was not in the spot namespace, and caused issues with some
    configurations of GCC.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
328
New in spot 2.4.4 (2017-12-25)
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
329

330
331
332
333
334
335
  Bugs fixed:

  - The generic to_generalized_buchi() function would fail if the
    Fin-less & CNF version of the acceptance condition had several
    unit clauses.

336
337
338
339
  - If the automaton passed to sbacc() was incomplete or
    non-deterministic because of some unreachable states, then it was
    possible that the output would marked similarly while it was in
    fact complete or deterministic.
340

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
341
New in spot 2.4.3 (2017-12-19)
342

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
343
  Bugs fixed:
344
345
346
347

  - couvreur99_new() leaked memory when processing TωA that allocate
    states.

348
349
  - Some mismatched placement-new/delete reported by ASAN were fixed.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
350
351
352
353
354
355
356
  - Static compilation was broken on MinGW.

  - Execution of Jupyter notebooks from the testsuite failed with
    recent versions of Python.

  - Fix some warnings triggered by the development version of g++.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
357
358
359
360
361
New in spot 2.4.2 (2017-11-07)

  Tools:

  - ltlcross and ltldo support ltl3tela, the new name of ltl3hoa.
362

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
363
364
365
366
367
  Bugs fixed:

  - Automata produced by "genaut --ks-nca=N" were incorrectly marked
    as not complete.

368
369
370
  - Fix some cases for which the highest setting of formulas
    simplification would produce worse results than lower settings.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
371
New in spot 2.4.1 (2017-10-05)
372

373
374
  Bugs fixed:

Maximilien Colange's avatar
Typos    
Maximilien Colange committed
375
376
  - The formula class failed to build {a->c[*]} although it is
    allowed by our grammar.
377

378
379
380
381
382
383
384
385
386
387
  - spot::scc_info::determine_unknown_acceptance() incorrectly
    considered some rejecting SCC as accepting.

  - spot::streett_to_generalized_buchi() could generate automata with
    empty language if some Fin set did not intersect all accepting
    SCCs.  As a consequence, some Streett-like automata were
    considered empty even though they were not.  Also, the same
    function could crash on input that had a Streett-like acceptance
    not using all declared sets.

Maximilien Colange's avatar
Typos    
Maximilien Colange committed
388
389
390
391
  - The twa_graph::merge_edges() function relied on BDD IDs to sort
    edges.  This in turn caused some algorithms (like the
    degeneralization) to produce slighltly different (but still correct)
    outputs depending on the BDD operations performed before.
392

Maximilien Colange's avatar
Typos    
Maximilien Colange committed
393
394
  - spot::simulation() could incorrectly flag an automaton as
    non-deterministic.
395

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
396
New in spot 2.4 (2017-09-06)
397

398
399
400
401
402
403
404
405
406
407
408
  Build:

  - Spot is now built in C++14 mode, so you need at least GCC 5 or
    clang 3.4.  The current version of all major linux distributions
    ship with at least GCC 6, which defaults to C++14, so this should
    not be a problem.  In *this* release of Spot, most of the header
    files are still C++11 compatible, so you should be able to include
    Spot in a C++11 project in case you do not yet want to upgrade.
    There is also an --enable-c++17 option to configure in case you
    want to force a build of Spot in C++17 mode.

409
410
  Tools:

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
411
412
413
414
415
416
417
418
  - genaut is a new binary that produces families of automata defined
    in the literature (in the same way as we have genltl for LTL
    formulas).

  - autcross is a new binary that compares the output of tools
    transforming automata (in the same way as we have ltlcross for
    LTL translators).

419
  - genltl learned two generate two new families of formulas:
420
421
422
423
424
425
      --fxg-or=RANGE         F(p0 | XG(p1 | XG(p2 | ... XG(pn))))
      --gxf-and=RANGE        G(p0 & XF(p1 & XF(p2 & ... XF(pn))))
    The later is a generalization of --eh-pattern=9, for which a
    single state TGBA always exists (but previous version of Spot
    would build larger automata).

426
  - autfilt learned to build the union (--sum) or the intersection
Maximilien Colange's avatar
Typos    
Maximilien Colange committed
427
428
    (--sum-and) of two languages by putting two automata side-by-side
    and fiddling with the initial states.  This complements the already
429
430
    implemented intersection (--product) and union (--product-or),
    both based on a product.
431

432
  - autfilt learned to complement any alternating automaton with
433
    option --dualize.   (See spot::dualize() below.)
Thomas Medioni's avatar
Thomas Medioni committed
434

435
436
437
438
  - autfilt learned --split-edges to convert labels that are Boolean
    formulas into labels that are min-terms.  (See spot::split_edges()
    below.)

439
440
441
  - autfilt learned --simplify-acceptance to simplify some acceptance
    conditions.  (See spot::simplify_acceptance() below.)

442
443
444
445
  - autfilt --decompote-strength has been renamed to --decompose-scc
    because it can now extract the subautomaton leading to an SCC
    specified by number.  (The old name is still kept as an alias.)

446
447
448
  - The --stats=%c option of tools producing automata can now be
    restricted to count complete SCCs, using %[c]c.

449
450
451
452
453
454
  - Tools producing automata have a --stats=... option, and tools
    producing formulas have a --format=... option.  These two options
    work similarly, the use of different names is just historical.
    Starting with this release, all tools that recognize one of these
    two options also accept the other one as an alias.

455
456
  Library:

457
458
  - A new library, libspotgen, gathers all functions used to generate
    families of automata or LTL formulas, used by genltl and genaut.
459

460
  - spot::sum() and spot::sum_and() implements the union and the
461
    intersection of two automata by putting them side-by-side and
462
    using non-deterministim or universal branching on the initial
463
    state.
464

465
466
467
  - twa objects have a new property: prop_complete().  This obviously
    acts as a cache for the is_complete() function.

Maximilien Colange's avatar
Typos    
Maximilien Colange committed
468
  - spot::dualize() complements any alternating automaton.  Since
469
470
471
    the dual of a deterministic automaton is still deterministic, the
    function spot::dtwa_complement() has been deprecated and simply
    calls spot::dualize().
472

473
474
475
476
477
478
  - spot::decompose_strength() was extended and renamed to
    spot::decompose_scc() as it can now also extract a subautomaton
    leading to a particular SCC.  A demonstration of this feature via
    the Python bindings can be found at
    https://spot.lrde.epita.fr/ipynb/decompose.html

479
480
  - The print_dot() function will now display names for well known
    acceptance conditions under the formula when option 'a' is used.
481
482
    We plan to enable 'a' by default in a future release, so a new
    option 'A' has been added to hide the acceptance condition.
483

484
485
486
487
488
  - The print_dot() function has a new experimental option 'x' to
    output labels are LaTeX formulas.  This is meant to be used in
    conjunction with the dot2tex tool.  See
      https://spot.lrde.epita.fr/oaut.html#dot2tex

489
490
491
492
  - A new named property for automata called "original-states" can be
    used to record the origin of a state before transformation.  It is
    currently defined by the degeneralization algorithms, and by
    transform_accessible() and algorithms based on it (like
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
493
494
495
496
497
    remove_ap::strip(), decompose_scc()).  This is realy meant as an
    aid for writing algorithms that need this mapping, but it can also
    be used to debug these algorithms: the "original-states"
    information is displayed by the dot printer when the 'd' option is
    passed.  For instance in
498
499
500
501
502
503
504

      % ltl2tgba 'GF(a <-> Fb)' --dot=s
      % ltl2tgba 'GF(a <-> Fb)' | autfilt -B --dot=ds

    the second command outputs an automaton with states that show
    references to the first one.

505
506
507
508
  - A new named property for automata called "degen-levels" keeps track
    of the level of a state in a degeneralization. This information
    complements the one carried in "original-states".

509
510
511
512
513
  - A new named property for automata called "simulated-states" can be
    used to record the origin of a state through simulation. The
    behavior is similar to "original-states" above. Determinization
    takes advantage of this in its pretty print.

514
515
516
517
518
519
  - The new function spot::acc_cond::is_streett_like() checks whether
    an acceptance condition is conjunction of disjunctive clauses
    containing at most one Inf and at most one Fin.  It builds a
    vector of pairs to use if we want to assume the automaton has
    Streett acceptance.  The dual function is
    spot::acc_cond::is_rabin_like() works similarly.
520

521
522
523
524
525
  - The degeneralize() function has learned to consider acceptance
    marks common to all edges comming to a state to select its initial
    level.  A similar trick was already used in sbacc(), and saves a
    few states in some cases.

526
527
528
529
530
531
532
  - There is a new spot::split_edges() function that transforms edges
    (labeled by Boolean formulas over atomic propositions) into
    transitions (labeled by conjunctions where each atomic proposition
    appear either positive or negative).  This can be used to
    preprocess automata before feeding them to algorithms or tools
    that expect transitions labeled by letters.

533
534
535
  - spot::scc_info has two new methods to easily iterate over the
    edges of an SCC: edges_of() and inner_edges_of().

536
537
538
  - spot::scc_info can now be passed a filter function to ignore
    or cut some edges.

539
540
541
542
543
  - spot::scc_info now keeps track of acceptance sets that are common
    to all edges in an SCC.  These can be retrieved using
    scc_info::common_sets_of(scc), and they are used by scc_info to
    classify some SCCs as rejecting more easily.

544
545
546
547
548
549
  - The new function acc_code::remove() removes all the given
    acceptance sets from the acceptance condition.

  - It is now possible to change an automaton acceptance condition
    directly by calling twa::set_acceptance().

550
551
552
553
554
  - spot::cleanup_acceptance_here now takes an additional boolean
    parameter specifying whether to strip useless marks from the
    automaton.  This parameter is defaulted to true, in order to
    keep this modification backward-compatible.

555
556
557
558
  - The new function spot::simplify_acceptance() is able to perform
    some simplifications on an acceptance condition, and might lead
    to the removal of some acceptance sets.

559
  - The function spot::streett_to_generalized_buchi() is now able to
560
    work on automata with Streett-like acceptance.
561

562
563
564
565
566
  - The function for converting deterministic Rabin automata to
    deterministic Büchi automata (when possible), internal to the
    remove_fin() procedure, has been updated to work with
    transition-based acceptance and with Rabin-like acceptance.

567
568
569
570
  - spot::relabel_here() was used on automata to rename atomic
    propositions, it can now replace atomic propositions by Boolean
    subformula.  This makes it possible to use relabeling maps
    produced by relabel_bse() on formulas.
571

572
573
574
575
  - twa_graph::copy_state_names_from() can be used to copy the state
    names from another automaton, honoring "original-states" if
    present.

576
577
  - Building automata for LTL formula with a large number N of atomic
    propositions can be costly, because several loops and
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
578
    data-structures are exponential in N.  However a formula like
579
580
581
582
583
584
585
586
      ((a & b & c) | (d & e & f)) U ((d & e & f) | (g & h & i))
    can be translated more efficiently by first building an automaton
    for (p0 | p1) U (p1 | p2), and then substituting p0, p1, p2 by the
    appropriate Boolean formula.  Such a trick is now attempted
    for translation of formulas with 4 atomic propositions or
    more (this threshold can be changed, see -x relabel-bool=N in
    the spot-x(7) man page).

587
588
589
590
  - The LTL simplification routines learned that an LTL formula like
    G(a & XF(b & XFc & Fd) can be simplified to G(a & Fb & Fc & Fd),
    and dually F(a | XG(b | XGc | Gd)) = F(a | Gb | Gc | Gd).

591
592
593
594
    When working with SERE, the simplification of "expr[*0..1]" was
    improved.  E.g. {{a[*]|b}[*0..1]} becomes {a[*]|b} instead of
    {{a[+]|b}[*0..1]}.

595
596
597
598
  - The new function spot::to_weak_alternating() is able to take an
    input automaton with generalized Büchi/co-Büchi acceptance and
    convert it to a weak alternating automaton.

599
600
  - spot::sbacc() is can now also convert alternating automata
    to state-based acceptance.
601

602
603
604
  - spot::sbacc() and spot::degeneralize() learned to merge
    accepting sinks.

605
  - If the SPOT_BDD_TRACE environment variable is set, statistics
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
606
607
    about BDD garbage collection and table resizing are shown.

608
  - The & and | operators for acceptannce conditions have been changed
609
    slightly to be more symmetrical.  In older versions, operator &
610
611
612
613
    would move Fin() terms to the front, but that is not the case
    anymore.  Also operator & was already grouping all Inf() terms
    (for efficiency reasons), in this version operator | is
    symmetrically grouping all Fin() terms.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
614

615
616
617
618
  - The automaton parser is now reentrant, making it possible to
    process automata from different streams at the same time (i.e.,
    using multiple spot::automaton_stream_parser instances at once).

619
620
621
622
623
624
625
626
627
  - The print_hoa() and parse_automaton() functions have been updated
    to recognize the "exist-branch" property of the non-released HOA
    v1.1, as well as the new meaning of property "deterministic".  (In
    HOA v1 "properties: deterministic" means that the automaton has no
    existential branching; in HOA v1.1 it disallows universal
    branching as well.)  The meaning of "deterministic" in Spot has
    been adjusted to these new semantics, see "Backward-incompatible
    changes" below.

Maximilien Colange's avatar
Typos    
Maximilien Colange committed
628
  - The parser for HOA now recognizes and verifies correct use of the
629
    "univ-branch" property.  This is known to be a problem with option
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
630
    -H1 of ltl3ba 1.1.2 and ltl3dra 0.2.4, so the environment variable
631
632
    SPOT_HOA_TOLERANT can be set to disable the diagnostic.

633
634
635
636
637
  Python:

  - The 'spot.gen' package exports the functions from libspotgen.
    See https://spot.lrde.epita.fr/ipynb/gen.html for examples.

638
639
640
641
  Bugs fixed:

  - When the remove_fin() function was called on some automaton with
    Inf-less acceptance involving at least one disjunction (e.g.,
Maximilien Colange's avatar
Typos    
Maximilien Colange committed
642
    generalized co-Büchi), it would sometimes output an automaton with
643
644
    transition-based acceptance but marked as state-based.

645
646
  - The complete() function could complete an empty co-Büchi automaton
    into an automaton accepting everything.
647

648
649
650
651
652
653
654
655
656
657
  Backward-incompatible changes:

  - spot::acc_cond::mark_t::operator bool() has been marked as
    explicit.  The implicit converion to bool (and, via bool, to int)
    was a source of bugs.

  - spot::twa_graph::set_init_state(const state*) has been removed.
    It was never used.  You always want to use
    spot::twa_graph::set_init_state(unsigned) in practice.

658
659
660
661
662
663
664
  - The previous implementation of spot::is_deterministic() has been
    renamed to spot::is_universal().  The new version of
    spot::is_deterministic() requires the automaton to be both
    universal and existential.  This should not make any difference in
    existing code unless you work with the recently added support for
    alternating automata.

665
666
667
  - spot::acc_cond::mark_t::sets() now returns an internal iterable
    object instead of an std::vector<unsigned>.

668
669
670
671
  - The color palette optionally used by print_dot() has been extended
    from 9 to 16 colors.  While the first 8 colors are similar, they
    are a bit more saturated now.

672
  deprecation notices:
673

674
  (these functions still work but compilers emit warnings.)
675

676
677
678
  - spot::decompose_strength() is deprecated, it has been renamed
    to spot::decompose_scc().

679
  - spot::dtwa_complement() is deprecated.  prefer the more generic
680
681
    spot::dualize() instead.

682
  - the spot::twa::prop_deterministic() methods have been renamed to
683
    spot::twa::prop_universal() for consistency with the change to
684
    is_deterministic() listed above.  we have kept
685
686
    spot::twa::prop_deterministic() as a deprecated synonym for
    spot::twa::prop_universal() to help backward compatibility.
687

688
  - the spot::copy() function is deprecated.  use
689
690
    spot::make_twa_graph() instead.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
691
New in spot 2.3.5 (2017-06-22)
692

693
694
  Bugs fixed:

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
695
  - We have fixed new cases where translating multiple formulas in a
696
697
    single ltl2tgba run could produce automata different from those
    produced by individual runs.
698

699
700
701
702
703
  - The print_dot() function had a couple of issues when printing
    alternating automata: in particular, when using flag 's' (display
    SCC) or 'y' (split universal destination by colors) universal
    edges could be connected to undefined states.

704
705
706
707
708
709
  - Using --stats=%s or --stats=%s or --stats=%t could take an
    unnecessary long time on automata with many atomic propositions,
    due to a typo.  Furthermore, %s/%e/%t/%E/%T were printing
    a number of reachable states/edges/transitions, but %S was
    incorrectly counting all states even unreachable.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
710
711
712
  - Our verson of BuDDy had an incorrect optimization for the
    biimp operator.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
713
New in spot 2.3.4 (2017-05-11)
714

715
716
  Bugs fixed:

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
717
  - The transformation to state-based acceptance (spot::sbacc()) was
718
    incorrect on automata where the empty acceptance mark is accepting.
719

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
720
  - The --help output of randaut and ltl2tgba was showing an
721
722
    unsupported %b stat.

723
724
725
  - ltldo and ltlcross could leave temporary files behind when
    aborting on error.

726
727
728
729
  - The LTL simplifcation rule that turns F(f)|q into F(f|q)
    when q is a subformula that is both eventual and universal
    was documented but not applied in some forgotten cases.

730
731
732
733
  - Because of some caching inside of ltl2tgba, translating multiple
    formula in single ltl2tgba run could produce automata different
    from those produced by individual runs.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
734
New in spot 2.3.3 (2017-04-11)
735

736
737
738
739
740
  Tools:

  - ltldo and ltlcross learned shorthands to talk to ltl2da, ltl2dpa,
    and ltl2ldba (from Owl) without needing to specify %f>%O.

741
  - genltl learned --spec-patterns as an alias for --dac-patterns; it
742
743
744
    also learned two new sets of LTL formulas under --hkrss-patterns
    (a.k.a. --liberouter-patterns) and --p-patterns
    (a.k.a. --beem-patterns).
745

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
746
  Bugs fixed:
747

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
748
749
  - In "lenient" mode the formula parser would fail to recover from a
    missing closing brace.
750

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
751
752
  - The output of 'genltl --r-left=1 --r-right=1 --format=%F' had
    typos.
753

754
755
756
757
  - 'ltl2tgba Fa | autfilt --complement' would incorrectly claim that
    the output is "terminal" because dtwa_complement() failed to reset
    that property.

758
759
760
  - spot::twa_graph::purge_unreachable_states() was misbehaving on
    alternating automata.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
761
762
  - In bench/stutter/ the .cc files were not compiling due to warnings
    being caught as errors.
763

764
765
766
767
768
769
  - The code in charge of detecting DBA-type Rabin automata is
    actually written to handle a slightly larger class of acceptance
    conditions (e.g., Fin(0)|(Fin(1)&Inf(2))), however it failed to
    correctly detect DBA-typeness in some of these non-Rabin
    acceptance.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
770
New in spot 2.3.2 (2017-03-15)
771

772
773
  Tools:

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
774
  - In tools that output automata, the number of atomic propositions
775
    can be output using --stats=%x (output automaton) or --stats=%X
776
    (input automaton).  Additional options can be passed to list
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
777
    atomic propositions instead of counting them.  Tools that output
778
    formulas also support --format=%x for this purpose.
779

780
781
  Python:

782
783
  - The bdd_to_formula(), and to_generalized_buchi() functions can now
    be called in Python.
784

785
786
787
788
789
  Documentation:

  - https://spot.lrde.epita.fr/tut11.html is a new page describing
    how to build monitors in Shell, Python, or C++.

790
791
792
793
794
  Bugs fixed:

  - The tests using LTSmin's patched version of divine would fail
    if the current (non-patched) version of divine was installed.

795
796
797
  - Because of a typo, the output of --stats='...%P...' was correct
    only if %p was used as well.

798
799
800
  - genltl was never meant to have (randomly attributed) short
    options for --postive and --negative.

801
802
803
804
  - a typo in the code for transformating transition-based acceptance
    to state-based acceptance could cause a superfluous initial state
    to be output in some cases (the result was still correct).

805
806
  - 'ltl2tgba --any -C -M ...' would not complete automata.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
807
  - While not incorrect, the HOA properties output by 'ltl2tgba -M'
808
809
810
811
    could be 'inherently-weak' or 'terminal', while 'ltl2tgba -M -D'
    would always report 'weak' automata.  Both variants now report the
    most precise between 'weak' or 'terminal'.

812
813
814
  - spot::twa_graph::set_univ_init_state() could not be called with
    an initializer list.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
815
  - The Python wrappers for spot::twa_graph::state_from_number and
816
817
    spot::twa_graph::state_acc_sets were broken in 2.3.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
818
  - Instantiating an emptiness check on an automaton with unsupported
819
820
821
822
    acceptance condition should throw an exception.  This used to be
    just an assertion, disabled in release builds; the difference
    matters for the Python bindings.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
823
  Deprecation notice:
824
825
826
827

  - Using --format=%a to print the number of atomic propositions in
    ltlfilt, genltl, and randltl still works, but it is not documented
    anymore and should be replaced by the newly-introduced --format=%x
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
828
829
    for consistency with tools producing automata, where %a means
    something else.
830

831

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
832
New in spot 2.3.1 (2017-02-20)
833

834
835
836
837
838
839
  Tools:

  - ltldo learnt to act like a portfolio: --smallest and --greatest
    will select the best output automaton for each formula translated.
    See https://spot.lrde.epita.fr/ltldo.html#portfolio for examples.

840
841
842
  - The colors used in the output of ltlcross have been adjusted to
    work better with white backgrounds and black backgrounds.

843
844
845
  - The option (y) has been added to --dot. It splits the universal
    edges with the same targets but different colors.

846
847
848
849
850
  - genltl learnt three new families for formulas: --kr-n2=RANGE,
    --kr-nlogn=RANGE, and --kr-n=RANGE.  These formulas, from
    Kupferman & Rosenberg [MoChArt'10] are recognizable by
    deterministic Büchi automata with at least 2^2^n states.

851
852
853
854
  Library:

  - spot::twa_run::as_twa() has an option to preserve state names.

855
856
857
858
  - the method spot::twa::is_alternating(), introduced in Spot 2.3 was
    badly named and has been deprecated.  Use the negation of the new
    spot::twa::is_existential() instead.

859
860
861
862
863
864
865
  Bugs fixed:

  - spot::otf_product() was incorrectly registering atomic
    propositions.

  - spot::ltsmin_model::kripke() forgot to register the "dead"
    proposition.
866

867
868
869
870
871
872
  - The spot::acc_word type (used to construct acceptance condition)
    was using some non-standard anonymous struct.  It is unlikely that
    this type was actually used outside Spot, but if you do use it,
    spot::acc_word::op and spot::acc_word::type had to be renamed as
    spot::acc_word::sub.op and spot::acc_word::sub.type.

873
874
875
  - alternation_removal() was not always reporting the unsupported
    non-weak automata.

876
877
878
879
  - a long-standing typo in the configure code checking for Python
    caused any user-defined CPPFLAGS to be ignored while building
    Spot.

880
881
882
883
  - The display of clusters with universal edges was confused, because the
    intermediate node was not in the cluster even if one of the target was
    in the same one.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
884
New in spot 2.3 (2017-01-19)
885

886
887
888
889
890
891
892
893
894
895
896
  Build:

  * While Spot only relies on C++11 features, the configure script
    learned --enable-c++14 to compile in C++14 mode.  This allows us
    check that nothing breaks when we will switch to C++14.

  * Spot is now distributed with PicoSAT 965, and uses it for
    SAT-based minimization of automata without relying on temporary
    files.  It is still possible to use an external SAT solver by
    setting the SPOT_SATSOLVER environment variable.

897
898
899
  * The development Debian packages for Spot now install static
    libraries as well.

900
901
  * We now install configuration files for users of pkg-config.

902
903
  Tools:

904
905
906
  * ltlcross supports translators that output alternating automata in
    the HOA format.  Cross-comparison checks will only work with weak
    alternating automata (not necessarily *very* weak), but "ltlcross
907
908
    --no-check --product=0 --csv=..." will work with any alternating
    automaton if you just want satistics.
909

910
911
912
913
914
915
  * autfilt can read alternating automata.  This is still experimental
    (see below). Some of the algorithms proposed by autfilt will
    refuse to work because they have not yet been updated to work with
    alternating automata, but in any case they should display a
    diagnostic: if you see a crash, please report it.

916
917
918
  * autfilt has three new filters: --is-very-weak, --is-alternating,
    and --is-semi-deterministic.

919
920
  * the --check option of autfilt/ltl2tgba/ltldo/dstar2tgba can now
    take "semi-determinism" as argument.
921

922
  * autfilt --highlight-languages will color states that recognize
923
    identical languages.  (Only works for deterministic automata.)
924

925
926
927
928
929
  * 'autfilt --sat-minimize' and 'ltl2tgba -x sat-minimize' have
    undergone some backward incompatible changes.  They use binary
    search by default, and support different options than they used
    too.  See spot-x(7) for details.  The defaults are those that were
    best for the benchmark in bench/dtgbasat/.
930

931
932
933
934
  * ltlfilt learned --recurrence and --persistence to match formulas
    belonging to these two classes of the temporal hierarchy.  Unlike
    --syntactic-recurrence and --syntactic-persistence, the new checks
    are automata-based and will also match pathological formulas.
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
935
    See https://spot.lrde.epita.fr/hierarchy.html
936

937
  * The --format option of ltlfilt/genltl/randltl/ltlgrind learned to
938
    print the class of a formula in the temporal hierarchy of Manna &
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
939
    Pnueli using %h.  See https://spot.lrde.epita.fr/hierarchy.html
940

941
942
943
944
945
946
  * ltldo and ltlcross learned a --relabel option to force the
    relabeling of atomic propositions to p0, p1, etc.  This is more
    useful with ltldo, as it allows calling a tool that restricts the
    atomic propositions it supports, and the output automaton will
    then be fixed to use the original atomic propositions.

947
948
949
  * ltldo and ltlcross have learned how to call ltl3hoa, so
    'ltl3hoa -f %f>%O' can be abbreviated to just 'ltl3hoa'.

950
951
952
  Library:

  * A twa is required to have at least one state, the initial state.
953
954
    An automaton can only be empty while it is being constructed,
    but should not be passed to other algorithms.
955

956
  * Couvreur's emptiness check has been rewritten to use the explicit
957
958
    interface when possible, to avoid overkill memory allocations.
    The new version has further optimizations for weak and terminal
959
960
961
    automata.  Overall, this new version is roughly 4x faster on
    explicit automata than the former one.  The old version has been
    kept for backward compatibility, but will be removed eventually.
962

963
  * The new version of the Couvreur emptiness check is now the default
964
965
    one, used by twa::is_empty() and twa::accepting_run().  Always
    prefer these functions over an explicit call to Couvreur.
966

967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
  * experimental support for alternating automata:

    - twa_graph objects can now represent alternating automata.  Use
      twa_graph::new_univ_edge() and twa_graph::set_univ_init_state()
      to create universal edges an initial states; and use
      twa_graph::univ_dests() to iterate over the universal
      destinations of an edge.

    - the automaton parser will now read alternating automata in the
      HOA format.  The HOA and dot printers can output them.

    - the file twaalgos/alternation.hh contains a few algorithms
      specific to alternating automata:
      + remove_alternation() will transform *weak* alternating automata
        into TGBA.
      + the class outedge_combiner can be used to perform "and" and "or"
        on the outgoing edges of some alternating automaton.

985
    - scc_info has been adjusted to handle universal edges as if they
986
987
988
      were existential edges.  As a consequence, acceptance
      information is not accurate.

989
990
991
992
993
994
995
    - postprocessor will call remove_alternation() right away, so
      it can be used as a way to transform alternating automata
      into different sub-types of (generalized) Büchi automata.
      Note that although prostprocessor optimize the resulting
      automata, it still has no simplification algorithms that work
      at the alternating automaton level.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
996
997
998
    - See https://spot.lrde.epita.fr/tut23.html
      https://spot.lrde.epita.fr/tut24.html and
      https://spot.lrde.epita.fr/tut31.html for some code examples.
999

1000
1001
1002
1003
  * twa objects have two new properties, very-weak and
    semi-deterministic, that can be set or retrieved via
    twa::prop_very_weak()/twa::prop_semi_deterministic(), and that can
    be tested by is_very_weak_automaton()/is_semi_deterministic().
1004

1005
1006
1007
1008
1009
1010
  * twa::prop_set has a new attribute used in twa::prop_copy() and
    twa::prop_keep() to indicate that determinism may be improved by
    an algorithm.  In other words properties like
    deterministic/semi-deterministic/unambiguous should be preserved
    only if they are positive.

1011
  * language_map() and highlight_languages() are new functions that
1012
    implement autfilt's --highlight-languages option mentionned above.
1013

1014
  * dtgba_sat_minimize_dichotomy() and dwba_sat_minimize_dichotomy()
1015
    use language_map() to estimate a lower bound for binary search.
1016

1017
  * The encoding part of SAT-based minimization consumes less memory.
1018

1019
1020
1021
1022
  * SAT-based minimization of automata can now be done using two
    incremental techniques that take a solved minimization and attempt
    to forbid the use of some states.  This is done either by adding
    clauses, or by using assumptions.
1023

1024
1025
1026
1027
  * If the environment variable "SPOT_XCNF" is set during incremental
    SAT-based minimization, XCNF files suitable for the incremental SAT
    competition will be generated.  This requires the use of an exteral
    SAT solver, setup with "SPOT_SATSOLVER".  See spot-x(7).
1028

1029
1030
1031
  * The new function mp_class(f) returns the class of the formula
    f in the temporal hierarchy of Manna & Pnueli.

1032
1033
1034
1035
1036
1037
1038
1039
1040
Python:

  * spot.show_mp_hierarchy() can be used to display the membership of
    a formula to the Manna & Pnueli hierarchy, in notebooks.  An
    example is in https://spot.lrde.epita.fr/ipynb/formulas.html

  * The on-line translator will now display the temporal hierarchy
    in the "Formula > property information" output.

1041
Bugs fixed:
1042
1043
1044
1045
1046
1047
1048
1049

  * The minimize_wdba() function was not correctly minimizing automata
    with useless SCCs.  This was not an issue for the LTL translation
    (where useless SCCs are always removed first), but it was an issue
    when deciding if a formula was safety or guarantee.  As a
    consequence, some tricky safety or guarantee properties were only
    recognized as obligations.

1050
1051
1052
1053
  * When ltlcross was running a translator taking the Spin syntax as
    input (%s) it would not automatically relabel any unsupported
    atomic propositions as ltldo already do.

1054
1055
1056
1057
  * When running "autfilt --sat-minimize" on a automaton representing
    an obligation property, the result would always be a complete
    automaton even without the -C option.

1058
1059
1060
  * ltlcross --products=0 --csv should not output any product-related
    column in the CSV output since it has nothing to display there.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1061
New in spot 2.2.2 (2016-12-16)
1062

1063
1064
1065
1066
1067
  Build:

  * If the system has an installed libltdl library, use it instead of
    the one we distribute.

1068
1069
1070
1071
  Bug fixes:

  * scc_filter() had a left-over print statement that would print
    "names" when copying the name of the states.
1072

1073
1074
1075
1076
1077
  * is_terminal() should reject automata that have accepting
    transitions going into rejecting SCCs.  The whole point of
    being a terminal automaton is that reaching an accepting
    transition guarantees that any suffix will be accepted.

1078
1079
1080
1081
1082
  * The HOA parser incorrectly read "Acceptance: 1 Bar(0)" as a valid
    way to specify "Acceptance: 1 Fin(0)" because it assumed that
    everything that was not Inf was Fin.  These errors are now
    diagnosed.

1083
1084
1085
1086
  * Some of the installed headers (spot/misc/fixpool.hh,
    spot/misc/mspool.hh, spot/twaalgos/emptiness_stats.hh) were not
    self-contained.

1087
1088
1089
  * ltlfilt --from-ltlf should ensure that "alive" holds initially in
    order to reject empty traces.

1090
1091
1092
  * the on-line translator had a bug where a long ltl3ba process would
    continue running even after the script had timeout'ed.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1093
New in spot 2.2.1 (2016-11-21)
1094

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1095
  Bug fix:
1096

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1097
1098
  * The bdd_noderesize() function, as modified in 2.2, would always
    crash.
1099

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1100
New in spot 2.2 (2016-11-14)
1101

1102
1103
1104
1105
1106
1107
  Command-line tools:

  * ltlfilt has a new option --from-ltlf to help reducing LTLf (i.e.,
    LTL over finite words) model checking to LTL model checking.  This
    is based on a transformation by De Giacomo & Vardi (IJCAI'13).

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1108
1109
1110
1111
  * "ltldo --stats=%R", which used to display the serial number of the
    formula processed, was renamed to "ltldo --stats=%#" to free %R
    for the following feature.

1112
1113
1114
  * autfilt, dstar2tgba, ltl2tgba, ltlcross, ltldo learned to measure
    cpu-time (as opposed to wall-time) using --stats=%R.  User or
    system time, for children or parent, can be measured separately by
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1115
1116
1117
1118
    adding additional %[LETTER]R options.  The difference between %r
    (wall-clock time) and %R (CPU time) can also be used to detect
    unreliable measurements.  See
      https://spot.lrde.epita.fr/oaut.html#timing
1119

1120
1121
  Library:

1122
1123
1124
  * from_ltlf() is a new function implementing the --from-ltlf
    transformation described above.

1125
  * is_unambiguous() was rewritten in a more efficient way.
1126

1127
  * scc_info learned to determine the acceptance of simple SCCs made
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1128
    of a single self-loop without resorting to remove_fin() for complex
1129
1130
1131
1132
1133
1134
    acceptance conditions.

  * remove_fin() has been improved to better deal with automata with
    "unclean" acceptance, i.e., acceptance sets that are declared but
    not used.  In particular, this helps scc_info to be more efficient
    at deciding the acceptance of SCCs in presence of Fin acceptance.
1135

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1136
1137
  * Simulation-based reductions now implement just bisimulation-based
    reductions on deterministic automata, to save time.  As an example,
1138
1139
1140
    this halves the run time of
       genltl --rv-counter=10 | ltl2tgba

1141
1142
  * scc_filter() learned to preserve state names and highlighted states.

1143
1144
1145
1146
1147
  * The BuDDy library has been slightly optimized: the initial setup
    of the unicity table can now be vectorized by GCC, and all calls
    to setjmp are now avoided when variable reordering is disabled
    (the default).

1148
1149
1150
1151
1152
1153
1154
1155
  * The twa class has three new methods:
      aut->intersects(other)
      aut->intersecting_run(other)
      aut->intersecting_word(other)
    currently these are just convenient wrappers around
      !otf_product(aut, other)->is_empty()
      otf_product(aut, other)->accepting_run()->project(aut)
      otf_product(aut, other)->accepting_word()
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1156
1157
1158
    with any Fin-acceptance removal performed before the product.
    However the plan is to implement these more efficiently in the
    future.
1159

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1160
  Bug fixes:
1161

1162
  * ltl2tgba was always using the highest settings for the LTL
1163
1164
1165
1166
    simplifier, ignoring the --low and --medium options.  Now
      genltl --go-theta=12 | ltl2tgba --low --any
    is instantaneous as it should be.

1167
1168
1169
  * The int-vector compression code could encode 6 and 22 in the
    same way, causing inevitable issues in our LTSmin interface.
    (This affects tests/ltsmin/modelcheck with option -z, not -Z.)
1170

1171
1172
1173
  * str_sere() and str_utf8_sere() were not returning the same
    string that print_sere() and print_utf8_sere() would print.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1174
  * Running the LTL parser in debug mode would crash.
1175

1176
  * tgba_determinize() could produce incorrect deterministic automata
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1177
    when run with use_simulation=true (the default) on non-simplified
1178
1179
    automata.

1180
1181
  * When the automaton_stream_parser reads an automaton from an
    already opened file descriptor, it will not close the file
1182
1183
1184
1185
    anymore.  Before that the spot.automata() python function used to
    close a file descriptor twice when reading from a pipe, and this
    led to crashes of the 0MQ library used by Jupyter, killing the
    Python kernel.
1186

1187
1188
1189
  * remove_fin() could produce incorrect result on incomplete
    automata tagged as weak and deterministic.

Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1190
1191
1192
  * calling set_acceptance() several times on an automaton could
    result in unexpected behaviors, because set_acceptance(0,...)
    used to set the state-based acceptance flag automatically.
1193

1194
  * Some buffering issue caused syntax errors to be displayed out
Alexandre Duret-Lutz's avatar
Alexandre Duret-Lutz committed
1195
    of place by the on-line translator.
1196

1197
New in spot 2.1.2 (2016-10-14)
1198

1199
1200
1201
1202
1203
1204
  Command-line tools:

  * genltl learned 5 new families of formulas
    (--tv-f1, --tv-f2, --tv-g1, --tv-g2, --tv-uu)
    defined in Tabakov & Vardi's RV'10 paper.

1205
1206
1207
1208
1209
1210
  * ltlcross's --csv and --json output was changed to not include
    information about the ambiguity or strength of the automata by
    default.   Computing those can be costly and not needed by
    every user, so it should now be requested explicitely using
    options --strength and --ambiguous.

1211
1212
1213
1214
1215
1216
1217
1218
  Library:

  * New LTL simplification rule:

    - GF(f & q) = G(F(f) & q) if q is
      purely universal and a pure eventuality.  In particular