Fixes#521.
* spot/tl/simplify.cc, spot/tl/simplify.hh,
spot/twaalgos/translate.cc, spot/twaalgos/translate.hh: Add an option
to limit automata-based implication checks of n-ary operators when too
many operands are used. Defaults to 16.
* bin/spot-x.cc, NEWS, doc/tl/tl.tex: Document it.
* tests/core/bdd.test: Disable the limit for this test.
Doing so reduced the number of GC passes tested in bdd.test, which is
good.
* spot/twaalgos/ltl2tgba_fm.cc: Simplify minato loops with
bdd_restrict.
* spot/twaalgos/synthesis.cc (split_2step): Use bdd_restrict instead
of bdd_appex.
* tests/core/bdd.test, tests/core/ltlf.test: Adjust test cases.
This restricts the time spent in translating sub-formulas for
implication tests by limiting the associated automata to 64 states by
default. Doing so this does worsen any test case, and actually remove
all calls the BuDDy's GC in bdd.test.
* spot/twaalgos/translate.cc, spot/twaalgos/translate.hh,
spot/tl/simplify.cc, spot/tl/simplify.hh, spot/tl/contain.hh,
spot/tl/contain.cc, spot/twaalgos/ltl2tgba_fm.cc,
spot/twaalgos/ltl2tgba_fm.hh: Add support for the option or
its constraint via an output_aborter.
* bin/spot-x.cc, NEWS: Document it.
* tests/core/bdd.test: Adjust and augment test case.
This fixes#412.
* spot/twaalgos/translate.cc: Add the quick syntactic simplification.
* spot/twaalgos/relabel.cc: Do not register old unused APs.
* tests/core/ltl2tgba2.test: Add test case.
* tests/core/bdd.test, tests/python/automata.ipynb: Adjust.
* NEWS: Mention this.
