and adjust it to detect siPSL formulas, as in the paper of Dax et
al. (ATVA'09). For issue #51.
* src/ltlast/atomic_prop.cc, src/ltlast/binop.cc,
src/ltlast/bunop.cc, src/ltlast/constant.cc, src/ltlast/formula.cc,
src/ltlast/formula.hh, src/ltlast/multop.cc, src/ltlast/unop.cc: Rename
the property, and adjust its computation on siSERE.
* src/ltlvisit/remove_x.cc, src/ltlvisit/simplify.cc,
src/tgbaalgos/stutter.cc: Adjust to new names.
* src/bin/ltlfilt.cc: Add option --syntactic-sutter-invariant.
* src/ltltest/kind.test: Update tests and add some new.
This operator is to ':' what [*i..j] is to ';'.
Part of issue #51.
* doc/tl/tl.tex: Document syntax, semantic, and trivial
simplifications.
* doc/tl/spotltl.sty: Add macros for new operators.
* src/ltlast/bunop.cc, src/ltlast/bunop.hh: Implement it.
* src/ltlast/multop.cc: Add some trivial simplifications.
* src/ltlparse/ltlparse.yy, src/ltlparse/ltlscan.ll: Parse it.
* src/ltltest/equals.test, src/ltltest/latex.test,
src/tgbatest/ltl2tgba.test: Add more tests.
* src/ltlvisit/randomltl.cc: Output this operator in
random PSL formulas.
* src/ltltest/rand.test: Adjust.
* src/tgbaalgos/ltl2tgba_fm.cc: Add translation rules.
* src/ltlvisit/tostring.cc: Add pretty printing code.
* src/ltlvisit/simplify.cc, src/ltlvisit/snf.cc: Adjust
switches.
* NEWS: Mention the new operator.
* src/ltlvisit/simplify.cc, doc/tl/tl.tex: Remove the rule.
* src/ltltest/reduc0.test: Add a regression test.
* src/ltltest/reduccmp.test: Adjust test cases for its removal.
* NEWS: Mention it.
This was only used in ELTL stuff, which I just removed because it was
unused.
* src/ltlast/automatop.cc, src/ltlast/automatop.hh,
src/ltlast/formula_tree.cc, src/ltlast/formula_tree.hh,
src/ltlast/nfa.cc, src/ltlast/nfa.hh: Delete.
* src/ltlast/Makefile.am: Adjust.
* src/ltlast/allnodes.hh, src/ltlast/formula.hh, src/ltlast/predecl.hh,
src/ltlast/visitor.hh, src/ltltest/equals.cc, src/ltltest/ltlrel.cc,
src/ltltest/reduc.cc, src/ltlvisit/clone.cc, src/ltlvisit/clone.hh,
src/ltlvisit/dotty.cc, src/ltlvisit/lbt.cc, src/ltlvisit/mark.cc,
src/ltlvisit/postfix.cc, src/ltlvisit/postfix.hh,
src/ltlvisit/relabel.cc, src/ltlvisit/simplify.cc, src/ltlvisit/snf.cc,
src/ltlvisit/tostring.cc, src/tgba/formula2bdd.cc,
src/tgbaalgos/ltl2taa.cc, src/tgbaalgos/ltl2tgba_fm.cc,
src/tgbaalgos/ltl2tgba_lacim.cc, src/tgbatest/ltl2tgba.cc,
iface/dve2/dve2check.cc: Remove all references to automatop.
star_normal_form() used to be called under bounded
repetitions like [*0..4], but some of these rewritings
are only correct for [*0..]. For instance
(a*|1)[*] can be rewritten to 1[*]
but (a*|1)[*0..1] cannot be rewritten to 1[*0..1]
it would be correct to rewrite the latter as (a[+]|1)[*0..1],
canceling the empty word in a*.
Also (a*;b*)[*] can be rewritten to (a|b)[*]
but (a*;b*)[*0..1] cannot be rewritten to (a|b)[*0..1]
and it cannot either be rewritten to (a[+]|b[+])[*0..1].
This patch introduces a new function to implement
rewritings under bounded repetition.
* src/ltlvisit/snf.hh, src/ltlvisit/snf.cc (star_normal_form_unbounded):
New function.
* src/ltlvisit/simplify.cc: Use it.
* src/ltltest/reduccmp.test: Add tests.
* doc/tl/tl.tex: Document the rewritings implemented.
Fortunately was only enabled with the
ltl_simplifier_options::favor_event_univ option, which cannot yet be
turned on from the command-line tools.
* src/ltlvisit/simplify.cc, doc/tl/tl.tex: Remove the rule.
* src/ltltest/eventuniv.test: Adjust.
* NEWS: Mention the bug.
* src/ltlvisit/simplify.cc: Remove two incorrect rules, and
partially disable another one.
* doc/tl/tl.tex: Reflect the change.
* src/ltltest/reduccmp.test: Likewise.
* src/ltltest/equals.cc: Add safety checks to catch such errors in the
future.
* NEWS: Mention the bug.
And also speedup implication checks for Boolean expressions.
* src/ltlvisit/simplify.cc: Improve implication-based rules
rules for multops by checking one operand against all the
other at once (instead of one by one). Do not break
Boolean expressions while performing implication checks.
* src/ltlvisit/simplify.hh: Typo.
* src/ltltest/reduccmp.test: More tests.
This follows from a discussion with Ernesto Posse.
The semantics for the {...} operator we use in Spot comes from the
cl(...) operator defined by Dax et al. (ATVA'09). This is slightly
different from the the way the PSL spec interprets a SERE used in the
context of a temporal formula (appendix B.3.1.1.2, item 7).
cl({a;b}[*]) would match any infinite word that starts with a;b, while
in PSL {a;b}[*] would match any infinite word that alternates a and b.
Spot documents that {SERE} in a temporal formula is interpreted like
cl(SERE) however it failed to ignore the empty prefix of SERE. So
{{a;b}[*]} would match anything, because the empty word is a prefix of
any word, and is also accepted by {a;b}[*]. Some trivial identities
and basic rewritings were also wrongly considering these empty
prefixes as well.
This patch therefore fixes the translation and syntactic
simplification rules, to really ignore these empty prefixes.
In some future version it should probably be wise to rename this {...}
operator as cl(...), and use {...} for the semantics given in appendix
B.3.1.1.2 (item 7) of the PSL specs.
* src/ltlast/unop.cc: Fix trivial identities. We have
{[*0]} = 0 and !{[*0]} = 1.
* src/ltlvisit/simplify.cc: Fix basic rewriting rules.
{e[*]} = {e} and !{e[*]} = !{e}.
* doc/tl/tl.tex: Adjust documentation.
* doc/tl/tl.bib (dax.09.atva): New entry.
* src/tgbaalgos/ltl2tgba_fm.cc: Do not accept any
infinite word for {e[*]} just because the empty
prefix is matched by e[*].
* src/tgbatest/ltl2tgba.test: Add a test case.
* NEWS: Mention it.
* THANKS: Add Ernesto.
The set of rules enabled by favor_even_univ try to "lift" the
subformulae that are both eventual and universal, so they appear
higher in the AST. This is contrary to what we used to do (and still
do when the option is unset), were we try to postpone such subformulae
(by moving them down the AST). It is still a bit experimental.
* src/ltlvisit/simplify.hh: Add option favor_event_univ.
* src/ltlvisit/simplify.cc: Implement new rewriting rules.
* doc/tl/tl.tex: Document them.
* src/tgbatest/ltl2tgba.cc: Add option -ra to enable them.
* src/tgbatest/spotlbtt.test: Test the translation with this option.
* src/ltltest/reduc.cc, src/ltltest/equals.cc: Add option
to enable the new rules.
* src/ltltest/eventuniv.test: New file to test them.
* src/ltltest/Makefile.am: Add it.
When something like XFa & FXa is reduced, the subformulae XFa and FXa
are both rewritten separately to XFa, and then the vector of arguments
of the And operators, [XFa,XFa], is passed through a specialized loop
that searches of the form X(...) that can potentially be simplified with
some other terms. This loop converts the vector [XFa,XFa] into the set
{XFa,XFa}={XFa} and forgot to deal with the case where the insertion
would actually not add an existing subformula.
* src/ltlvisit/simplify.cc: Fix the code for Or, and And.
* src/ltltest/reduc0.test: New file, to test it.
* src/ltltest/Makefile.am (TESTS): Add it.
* src/ltltest/reduccmp.test: Add an extra test that does not
trigger the bug (because reduccmp.test uses more than basic
optimizations, and the implication-based simplifications are
already able to detect that XFa and FXa are equivalent).
* src/eltlparse/Makefile.am, src/ltlvisit/randomltl.cc,
src/ltlvisit/simplify.cc, src/ltlvisit/snf.cc, src/ltlvisit/snf.hh:
Fix GPL to version 2 or later.
Doing so will release all BDD variables used by automata created for
syntactic implication. This way the main translation will create
acceptance variables again in a more natural order, which will help
the degeneralization (until we get a better degeneralization).
* src/ltlvisit/contain.cc, src/ltlvisit/contain.hh
(language_containment_checker::clear): New method to clear the
containment cache.
* src/ltlvisit/simplify.cc, src/ltlvisit/simplify.hh
(clear_as_bdd_cache): Also call language_containment_checker::clear.
Syntactic implication checks may use as_bdd() to compare Boolean
formulae. By doing so, they register Boolean variables in an order
that is usially detrimental to the LTL translator. The new,
clear_as_bdd_cache() function offers a mean to unregister these
variables, so that the LTL translator will register them again in the
a more natural way.
* src/ltlvisit/simplify.hh, src/ltlvisit/simplify.cc
(clear_as_bdd_cache): New function.
* src/tgbatest/ltl2tgba.cc, wrap/python/ajax/spot.in: Call it.
* src/ltlvisit/simplify.cc
(ltl_simplifier_cache::syntactic_implication): If the lhs and rhs are
literals that are not equal, return false immediately.
We need a marked version of !{r} to perform breakpoint unroling.
* src/ltlast/unop.cc, src/ltlast/unop.hh: Declare a NegClosureMarked
operator.
* src/ltlvisit/mark.hh, src/ltlvisit/mark.cc,
src/tgbaalgos/ltl2tgba_fm.cc: Adjust to deal with NegClosureMarked
and NegClosure as apropriate.
* src/ltlvisit/simplify.cc, src/ltlvisit/tostring.cc,
src/ltlvisit/tunabbrev.cc, src/tgbaalgos/eltl2tgba_lacim.cc,
src/tgbaalgos/ltl2taa.cc, src/tgbaalgos/ltl2tgba_lacim.cc,
src/tgba/formula2bdd.cc: Deal with NegClosureMarked in the same way as
we deal with NegClosure.
* src/tgbatest/ltl2tgba.test: More tests.
* src/ltltest/kind.test: Adjust.
* doc/tl/tl.tex: Mention the marked negated closure.
* src/ltlvisit/simplify.cc (reduce_sere_ltl): New function,
to factor the code of the []-> and <>-> rewrittings.
* src/ltltest/reduccmp.test: Add more tests.
* doc/tl/tl.tex: Document these rewritings.
* src/ltlvisit/simplify.cc: Here.
* doc/tl/tl.tex: Document then.
* src/ltlast/bunop.hh (as_KleenStar): New helper function.
* src/ltltest/reduccmp.test: Add more tests.
* src/ltltest/reduc.cc: Also display the resulting formula
without reduce_size_stricly.
* src/ltlvisit/snf.cc, src/ltlvisit/snf.hh: New files.
* src/ltlvisit/Makefile.am: Distribute them.
* src/ltlvisit/simplify.cc, src/ltlvisit/simplify.hh: Call snf(f) for
all f[*].
* src/ltltest/reduccmp.test: Test it.
* doc/tl/tl.tex, doc/tl/tl.bib: Document it.
It was a mistake to try to overload And/Or LTL operator for these when
trivial simplification are performed. The reason is so simple it is
embarassing: And(f,1)=f is a trivial identity that should not be
applied with AndRat. E.g. AndRat(a;b, 1) is equal to 0, not a;b.
* src/ltlast/multop.hh, src/ltlast/multop.cc: Add the AndRat and OrRat
operators.
* src/ltlparse/ltlparse.yy: Build them.
* src/ltlvisit/mark.cc, src/ltlvisit/simplify.cc,
src/ltlvisit/tostring.cc, src/tgba/formula2bdd.cc,
src/tgbaalgos/eltl2tgba_lacim.cc, src/tgbaalgos/ltl2taa.cc,
src/tgbaalgos/ltl2tgba_fm.cc, src/tgbaalgos/ltl2tgba_lacim.cc:
Adjust all switches.
