* src/ltlvisit/contain.hh (reduce_tau03): Mark as deprecated.
* src/tgbaalgos/ltl2tgba_fm.cc, src/tgbatest/ltl2tgba.cc,
src/ltltest/equals.cc: Do not include ltlvisit/contain.hh, since
it's not used.

* src/ltlvisit/basicreduce.cc, src/ltlvisit/basicreduce.hh: Delete.
* src/ltlvisit/Makefile.am: Remove them.

* src/ltlvisit/reduce.hh: Mark the file as obsolete.
(reduce): Declare this function as obsolete.
* src/ltlvisit/reduce.cc: Define SKIP_DEPRECATED_WARNING
so we can include reduce.hh.
* src/sanity/includes.test: Also use SKIP_DEPRECATED_WARNING
when compiling headers.
* iface/dve2/dve2check.cc,
src/ltltest/equals.cc, src/ltltest/randltl.cc,
src/ltltest/reduc.cc, src/tgbaalgos/ltl2tgba_fm.hh,
src/tgbaalgos/ltl2tgba_fm.cc, src/tgbatest/randtgba.cc,
wrap/python/ajax/spot.in, wrap/python/spot.i: Adjust
to use ltl_simplifier.
* src/tgbatest/ltl2tgba.cc: Adjust to use ltl_simplifier,
and replace -fr1...-fr7 options by a single -fr option.
* src/tgbatest/spotlbtt.test: Adjust -fr flags accordingly.
* src/tgbatest/reductgba.cc: Do not include reduce.hh.

* src/ltlvisit/simplify.hh
(ltl_simplifier::negative_normal_form): Allow logical
unabbreviations during the NNF pass.
* src/ltlvisit/simplify.cc
(ltl_simplifier::negative_normal_form)
(negative_normal_form_visitor): Adjust.
(ltl_simplifier::simplify): Request unabbreviations.
* src/ltlvisit/reduce.cc (reduce): Remove most
of the code, leaving only a call ltl_simplifier
and some wrapper code to convert options.
* src/ltltest/reduccmp.test: Add more test cases.

* src/ltlvisit/simplify.cc (simplify_visitor): Fix it,
and leave the trace code.

* src/ltlvisit/simplify.cc (ltl_simplifier::simplify):
Convert in negative normal form if needed.
* src/ltlvisit/reduce.cc (reduce): Do not call
negative_normal_form().

* src/ltlvisit/simplify.cc: Integrate the tau03
containment rules.
* src/ltlvisit/simplify.hh: Add options to select simplifications.
* src/ltlvisit/reduce.cc (reduce): Do not call reduce_tau03().
* src/ltlvisit/contain.cc (reduce_tau03_visitor): Remove.
(reduce_tau03): Implement it using ltl_simplifier.

* src/ltlvisit/simplify.cc (ltl_simplifier): Adjust
code.
* src/ltltest/reduccmp.test: Add some test cases.

* src/ltlvisit/simplify.cc (ltl_simplifier): Add more rewritings
for formulae that are both universal and eventual.
* src/ltltest/reduccmp.test: Add six more cases.

* src/ltltest/reduccmp.test: Add the test.

* src/ltlvisit/simplify.cc (ltl_simplifier): Since we are processing
the formula bottom-up, don't assume all trivial simplification have
been done.
* src/ltltest/reduccmp.test: More tests.

So far I have only checked these rewritings with reduccmp.test.
There are probably a few kinks to iron out.

* src/ltlvisit/simplify.cc: Reimplement most of the basic
rewriting rules, leaving some FIXME comments for dubious ones.
* src/ltlast/multop.cc, src/ltlast/multop.hh: Ignore NULL
pointers in the vector.
* src/ltlvisit/reduce.cc (reduce): Do not call basic_reduce().
* src/ltltest/reduccmp.test: Adjust tests.

* src/ltlvisit/reduce.cc (reduce_visitor): Move ...
* src/ltlvisit/simplify.cc (simplify_visitor): ... here, and
adjust to use the new ltl_simplifier_options.
* src/ltlvisit/reduce.cc (reduce): Use ltl_simplifier
to perform the work of reduce_visitor.  Eventually we want to
get rid of reduce.cc.
* src/ltlvisit/reduce.hh (reduce): Remove the
syntactic_implication_cache used as third argument.

* src/ltltest/kind.test: More pure eventualities and purely
universal properties are detected.

* src/ltlvisit/basicreduce.cc: Do not test
for things like X(true), F(false), or `a U 1`.
These are all trivial identities.

* src/ltlast/binop.cc (binop::binop): Generalize detection
of pure eventualities and purely universal formulae.  E.g.
`f U g' is a pure eventuality if g is a pure eventuality
(regardless of f) or if g is 1.
* src/ltlast/unop.cc (unop::unop): Compute is.eventual
and is.universal for Not.
* src/ltltest/kind.test: Adjust.

It is limited to negative_normal_form_visitor for now.

* src/ltlvisit/simplify.cc, src/ltlvisit/simplify.hh: New files.
* src/ltlvisit/Makefile.am: Add them.
* src/ltlvisit/nenoform.cc, src/ltlvisit/nenoform.hh: Rewrite
using ltl_simplifier.

* src/tgbatest/randpsl.test: Run without valgrind, it is too
slow otherwise.

I.e., SERE without star, or LTL formula using only X and Boolean
operators.

* src/ltlast/formula.hh, src/ltlast/formula.cc: Add a bit for
tracking finite formulas.
* src/ltlast/atomic_prop.cc, src/ltlast/automatop.cc,
src/ltlast/bunop.cc, src/ltlast/constant.cc, src/ltlast/formula.cc:
Adjust.
* src/ltlast/unop.cc, src/ltlast/binop.cc: Adjust and use that
bit to refine the computation of some LTL classes.
* src/ltltest/kind.test: New tests.

These are safety, guarantee, obligation, persistence, and recurrence.

* src/ltlast/formula.hh, src/ltlast/formula.cc: Declare a bit for
each of these classes.
* src/ltlast/atomic_prop.cc, src/ltlast/constant.cc,
src/ltlast/automatop.cc, src/ltlast/binop.cc, src/ltlast/bunop.cc,
src/ltlast/unop.cc: Update these bits.
* src/ltltest/kind.test: Update tests and add more.

* src/ltlast/multop.cc (multop::instance): Implement
the rewriting.   "a:b:c[*]:d:e" becomes "{{a&&b}&c[*]}:{d&&e}".
* src/ltlast/multop.hh: Document it.
* src/ltltest/equals.test, src/ltltest/kind.test: Add test cases.

* src/ltlast/binop.cc (EConcat, UConcat): Rewrite "{b}<>-> f"
as "b && f", and rewrite "{b}[]->f" as "b->f".
* src/ltlast/binop.hh (binop::instance): Document trivial
identities for <>-> and []->.
* src/ltlast/multop.cc (multop::instance): Rewrite "b1 & b2"
as "b1 && b2" when b1 and b2 are Boolean.
(multop::multop): Always disable is.boolean for AndNLM.
* src/ltlast/multop.hh: Document the rewriting.
* src/ltltest/equals.cc: Show the two formulas if the exit_code
is 1, to help debugging.
* src/ltltest/equals.test: Add more tests.
* src/ltltest/kind.test: Adjust tests.

* src/ltlvisit/randomltl.cc (random_formula::update_sums): Remove
duplicate semicolon.

* src/ltlvisit/contain.cc (recurse, reduce_tau03): Do not
run on non-PSL formulae.
* src/ltlvisit/reduce.cc (reduce_visitor::visit): Skip
multop::Fusion operators, and do not run syntactic_implication_neg
on SERE formulae.
* src/ltlvisit/syntimpl.cc (inf_right_recurse_visitor::visit):
Skip [*0].

* src/ltlast/atomic_prop.cc, src/ltlast/automatop.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: Add a bit is.sere_formula
to track SEREs, and fix tracking of PSL formulae.
* src/ltltest/kind.test: Adjust.

* src/ltlparse/ltlscan.ll: Recognize }!.  Also remove
five duplicate rules.
* src/ltlparse/ltlparse.yy: Build {r}<>->1 when parsing {r}!.
* src/ltlvisit/tostring.cc: Print {r}! instead of {r}<>->1.
* src/ltltest/tostring.test, src/ltltest/equals.test:
Add more tests.

* src/ltlast/bunop.hh, src/ltlast/multop.hh: Reorder some comments.

We still don't have any PSL-specific reductions, but at least
the LTL reduction now appear to work on PSL formulas.

* src/ltlvisit/basicreduce.cc (basic_reduce_visitor): Fix the
call to std::copy to handle Concat, Fusion, and AndNLM.
* src/ltlvisit/reduce.cc (reduce_visitor): Fix handling
of UConcat, EConcat, and EConcatMarked.
* src/tgbatest/randpsl.test: Activate reductions.
* src/ltltest/reducpsl.test: New file.
* src/ltltest/Makefile.am (TESTS): Add it.

* src/ltlvisit/randomltl.hh (random_formula::~random_formula):
Declare as virtual.

* src/tgbatest/randpsl.test: New file.
* src/tgbatest/Makefile.am (TESTS): Add it.

* src/tgbaalgos/ltl2tgba_fm.cc (ratexp_trad_visitor::visit):
Use a different translating rule for E* if E accepts [*0].
* src/tgbatest/ltl2tgba.test: Add test case.

* src/ltlvisit/randomltl.cc, src/ltlvisit/randomltl.hh:
(random_boolean, random_sere, random_psl): Add new classes.
* src/ltltest/randltl.cc: Add options to support the above.
Nore: the -p option was renamed to -pL for consistency, but
it is still understood.

* src/ltlvisit/tostring.hh, src/ltlvisit/tostring.cc (to_string):
Add third option to enable formating suitable for SERE.

* src/ltlparse/ltlparse.yy (rationalexp): Allow ->, <->, and xor,
in rational expressions as long as they apply only to Boolean
formulae.
* src/tgbaalgos/ltl2tgba_fm.cc (ratexp_trad_visitor): Adjust
assert in handling of unop::Not.

* src/ltlast/bunop.cc (bunop::bunop): Ensure it using an assert.

* src/ltlvisit/randomltl.hh (random_ltl): Split this class into...
(random_formula, random_ltl): ... these.
* src/ltlvisit/randomltl.cc: New