New function, performing LTL reduction a la tauriainen.03.a83.
* src/ltltest/equals.cc, src/ltltest/reduc.cc: Add support for
the new reduction.
* src/ltltest/reduc.test: Cut the test in half, and additionally
test the new reduction.
* src/ltltest/reduccmp.test: Run on the new reduction.
* src/ltltest/Makefile.am: Adjust.
* src/tgbatest/ltl2tgba.cc: Add new options to apply the reduction.
* src/tgbatest/spotlbtt.test: Use them.

* src/ltlvisit/Makefile.am (ltlvisit_HEADERS,
libltlvisit_la_SOURCES): Distribute them.
* src/ltltest/randltl.cc: New file.
* src/ltltest/Makefile.am (LDADD): Link with ../libspot.la directly.
(noinst_PROGRAMS, randltl_SOURCES): New.
(EXTRA_DIST, CLEANFILES): The list of random formulae is now generated.
* src/ltltest/formulae.txt: Delete.
* src/ltltest/reduc.test: Use randltl to generate formulae.
* src/ltlvisit/length.cc (length_visitor): Fix computation
of the length of multops.
* src/ltlvisit/length.hh (length): Document the length of multops.

automata.
* src/tgbatest/spotlbtt.test, src/tgbatest/Makefile.am: Add some
test for reduction of automata.
* src/tgbaalgos/reductgba_sim_del.cc, src/tgbaalgos/reductgba_sim.cc,
src/tgbaalgos/reductgba_sim.hh: Compute some simulation relation
to reduce a tgba.
* src/tgba/tgbareduc.cc, src/tgba/tgbareduc.hh: A implementation
of tgba for the reduction.
* src/tgbaalgos/Makefile.am, src/tgba/Makefile.am:
Add the reduction of automata.
* src/ltlvisit/syntimpl.cc, src/ltlvisit/basereduc.cc:
Lot of mistake are corrected.
* src/ltlvisit/syntimpl.hh, src/ltlvisit/reducform.cc,
src/ltlvisit/reducform.hh, src/ltltest/reduc.cc: Adjust.
* src/ltltest/equals.cc, src/ltltest/reduccmp.test,
src/ltltest/Makefile.am: Add a test for reduction.

* src/ltltest/syntimpl.cc, src/ltltest/syntimpl.test: ... these.
* src/ltltest/Makefile.am: Adjust.
* src/ltlvisit/forminf.cc: Rename as...
* src/ltlvisit/syntimpl.cc: ... this.
* src/ltlvisit/syntimpl.hh: New file with definitions extracted
from ...
* src/ltlvisit/reducform.hh: ... this one.
* src/ltlvisit/Makefile.am, src/ltlvisit/reducform.cc: Adjust.

* src/ltltest/formulae.txt: New files (2200 LTL formulea generated
by Wring).
* src/ltltest/formules.ltl: Delete.
* src/reduc.test: Read formulae.txt.

* src/ltltest/Makefile.am (CLEANFILES): Clean result.data.

* Makefile.am, configure.ac, doc/Makefile.am, iface/Makefile.am,
iface/gspn/Makefile.am, iface/gspn/common.cc,
iface/gspn/common.hh, iface/gspn/dottyeesrg.cc,
iface/gspn/dottygspn.cc, iface/gspn/eesrg.cc, iface/gspn/eesrg.hh,
iface/gspn/gspn.cc, iface/gspn/gspn.hh, iface/gspn/ltlgspn.cc,
src/Makefile.am, src/ltlast/Makefile.am, src/ltlast/allnodes.hh,
src/ltlast/atomic_prop.cc, src/ltlast/atomic_prop.hh,
src/ltlast/binop.cc, src/ltlast/binop.hh, src/ltlast/constant.cc,
src/ltlast/constant.hh, src/ltlast/formula.cc,
src/ltlast/formula.hh, src/ltlast/multop.cc, src/ltlast/multop.hh,
src/ltlast/predecl.hh, src/ltlast/refformula.cc,
src/ltlast/refformula.hh, src/ltlast/unop.cc, src/ltlast/unop.hh,
src/ltlast/visitor.hh, src/ltlenv/Makefile.am,
src/ltlenv/defaultenv.cc, src/ltlenv/defaultenv.hh,
src/ltlenv/environment.hh, src/ltlparse/Makefile.am,
src/ltlparse/fmterror.cc, src/ltlparse/ltlparse.yy,
src/ltlparse/ltlscan.ll, src/ltlparse/parsedecl.hh,
src/ltlparse/public.hh, src/ltltest/Makefile.am,
src/ltltest/defs.in, src/ltltest/equals.cc,
src/ltltest/equals.test, src/ltltest/lunabbrev.test,
src/ltltest/nenoform.test, src/ltltest/parse.test,
src/ltltest/parseerr.test, src/ltltest/readltl.cc,
src/ltltest/tostring.cc, src/ltltest/tostring.test,
src/ltltest/tunabbrev.test, src/ltltest/tunenoform.test,
src/ltlvisit/Makefile.am, src/ltlvisit/clone.cc,
src/ltlvisit/clone.hh, src/ltlvisit/destroy.cc,
src/ltlvisit/destroy.hh, src/ltlvisit/dotty.cc,
src/ltlvisit/dotty.hh, src/ltlvisit/dump.cc, src/ltlvisit/dump.hh,
src/ltlvisit/lunabbrev.cc, src/ltlvisit/lunabbrev.hh,
src/ltlvisit/nenoform.cc, src/ltlvisit/nenoform.hh,
src/ltlvisit/postfix.cc, src/ltlvisit/postfix.hh,
src/ltlvisit/tostring.cc, src/ltlvisit/tostring.hh,
src/ltlvisit/tunabbrev.cc, src/ltlvisit/tunabbrev.hh,
src/misc/Makefile.am, src/misc/bddalloc.cc, src/misc/bddalloc.hh,
src/misc/bddlt.hh, src/misc/hash.hh, src/misc/minato.cc,
src/misc/minato.hh, src/misc/version.cc, src/misc/version.hh,
src/tgba/Makefile.am, src/tgba/bdddict.cc, src/tgba/bdddict.hh,
src/tgba/bddprint.cc, src/tgba/bddprint.hh, src/tgba/public.hh,
src/tgba/state.hh, src/tgba/statebdd.cc, src/tgba/statebdd.hh,
src/tgba/succiter.hh, src/tgba/succiterconcrete.cc,
src/tgba/succiterconcrete.hh, src/tgba/tgba.cc, src/tgba/tgba.hh,
src/tgba/tgbabddconcrete.cc, src/tgba/tgbabddconcrete.hh,
src/tgba/tgbabddconcretefactory.cc,
src/tgba/tgbabddconcretefactory.hh,
src/tgba/tgbabddconcreteproduct.cc,
src/tgba/tgbabddconcreteproduct.hh, src/tgba/tgbabddcoredata.cc,
src/tgba/tgbabddcoredata.hh, src/tgba/tgbabddfactory.hh,
src/tgba/tgbaexplicit.cc, src/tgba/tgbaexplicit.hh,
src/tgba/tgbaproduct.cc, src/tgba/tgbaproduct.hh,
src/tgba/tgbatba.cc, src/tgba/tgbatba.hh,
src/tgbaalgos/Makefile.am, src/tgbaalgos/dotty.cc,
src/tgbaalgos/dotty.hh, src/tgbaalgos/dupexp.cc,
src/tgbaalgos/dupexp.hh, src/tgbaalgos/emptinesscheck.cc,
src/tgbaalgos/emptinesscheck.hh, src/tgbaalgos/lbtt.cc,
src/tgbaalgos/lbtt.hh, src/tgbaalgos/ltl2tgba_fm.cc,
src/tgbaalgos/ltl2tgba_fm.hh, src/tgbaalgos/ltl2tgba_lacim.cc,
src/tgbaalgos/ltl2tgba_lacim.hh, src/tgbaalgos/magic.cc,
src/tgbaalgos/magic.hh, src/tgbaalgos/reachiter.cc,
src/tgbaalgos/reachiter.hh, src/tgbaalgos/save.cc,
src/tgbaalgos/save.hh, src/tgbaparse/Makefile.am,
src/tgbaparse/fmterror.cc, src/tgbaparse/parsedecl.hh,
src/tgbaparse/public.hh, src/tgbaparse/tgbaparse.yy,
src/tgbaparse/tgbascan.ll, src/tgbatest/Makefile.am,
src/tgbatest/bddprod.test, src/tgbatest/defs.in,
src/tgbatest/dupexp.test, src/tgbatest/emptchk.test,
src/tgbatest/emptchke.test, src/tgbatest/explicit.test,
src/tgbatest/explpro2.test, src/tgbatest/explpro3.test,
src/tgbatest/explprod.test, src/tgbatest/ltl2tgba.test,
src/tgbatest/ltlprod.test, src/tgbatest/mixprod.test,
src/tgbatest/readsave.test, src/tgbatest/spotlbtt.test,
src/tgbatest/tgbaread.test, src/tgbatest/tripprod.test,
wrap/Makefile.am, wrap/python/Makefile.am, wrap/python/buddy.i,
wrap/python/spot.i, wrap/python/cgi/Makefile.am,
wrap/python/cgi/ltl2tgba.in, wrap/python/tests/Makefile.am,
wrap/python/tests/bddnqueen.py, wrap/python/tests/interdep.py,
wrap/python/tests/ltl2tgba.py, wrap/python/tests/ltl2tgba.test,
wrap/python/tests/ltlparse.py, wrap/python/tests/ltlsimple.py,
wrap/python/tests/run.in: Add Copyright license.

* tgba/bdddict.hh (bdd_dict::register_propositions,
bdd_dict::register_accepting_variables): New methods.
* src/bdddict.cc: Likewise.
* tgba/tgbaexplicit.cc (tgba_explicit::add_conditions,
tgba_explicit::add_accepting_conditions): New methods.
(tgba_explicit::get_init_state): Add an "empty" initial
state to empty automata.
* tgba/tgbaexplicit.hh: (tgba_explicit::add_conditions,
tgba_explicit::add_accepting_conditions): New methods.
* tgbaalgos/Makefiles.am (tgbaalgos_HEADERS, libtgbaalgos_la_SOURCES):
Add dupexp.hh and dupexp.cc.
* tgbaalgos/dupexp.hh, tgbaalgos/dupexp.cc: New files.
* tgbatest/Makefile.am (AM_CXXFLAGS): New variable.
(check_SCRIPTS): Add dupexp.test.
(CLEANFILES): Add output1 and output2.
* tgbatest/dupexp.test: New file.
* tgbatest/ltl2tgba.cc: Handle -s and -S.
* tgbatest/tgbaread.cc: Remove unused variable exit_code.

* src/ltlvisit/tostring.hh (to_string): Add doxygen comments.
* src/ltlast/multop.hh (multop::paircmp): Add doxygen comments.
* src/ltlvisit/postfix.hh: Typo.

reference-counted formula*.  One can't call constructors for AST
items anymore, everything need to be acquired through instance()
class methods.

* src/ltlast/formula.cc, src/ltlast/refformula.cc,
src/ltlast/refformula.hh: New files.
* src/ltlast/Makefile.am (libltlast_la_SOURCES): Add them.
* src/ltlast/atomic_prop.cc, src/ltlast/atomic_prop.hh,
src/ltlast/unop.cc, src/ltlast/unop.hh,
src/ltlast/binop.cc, src/ltlast/binop.hh: Make the constructor
and destructor protected.  Define a static function `instance()'
to get an instance with specific argument.  Use a map called
`instances' to store all known instances.  Inherit from
ref_formula.
* src/ltlast/constant.hh, src/ltlast/constant.cc: Protect
the constructor and destructor.  Provide the false_instance()
and true_instance() functions instead.
* src/formula.hh (ref, unref, ref_, unref_): New methods.
* src/ltlast/multop.cc, src/ltlast/multop.hh: Protect
the constructor, destructor, as well as the add() method.
Provides the instance(), and add() class methods instead.
Store children_ as a pointer.
* src/ltlenv/defaultenv.cc (require): Adjust to
call atomic_prop::instance.
* src/ltlparse/ltlparse.yy: Adjust to call instance() functions
instead of constructors.
* src/ltltest/Makefile.am (LDADD): Tweak library ordering.
* src/ltlvisit/clone.hh (clone_visitor): Inherit from visitor,
not const_visitor, and adjust all prototypes appropriately.
* src/ltlvisit/clone.cc (clone_visitor): Likewise.
Call ref() or instance() methods instead of copy constructors.
* src/ltlvisit/equals.cc: Simplify atomic_prop and constant
cases.
* src/ltlvisit/lunabbrev.hh, src/ltlvisit/lunabbrev.cc,
src/ltlvisit/tunabbrev.hh, src/ltlvisit/tunabbrev.cc,
src/ltlvisit/nenoform.hh, src/ltlvisit/nenoform.cc: Use instance()
methods instead of constructor.  Make these children of visitor, not
const_visitor.
* src/ltltest/readltl.c (main): Do not delete the formula.

* src/ltlast/Makefile.am, src/ltlenv/Makefile.am,
src/ltlparse/Makefile.am, src/ltltest/Makefile.am,
src/ltlvisit/Makefile.am: Adust to build libtool libraries.

* src/ltltest/tostring.cc: New files.
* src/ltlvisit/tostring.hh: From ast to string New files.
* src/ltlvisit/tostring.cc: From ast to string New files.

* src/ltlenv/Makefile.am, src/ltlenv/defaultenv.cc,
src/ltlenv/defaultenv.hh, src/ltlenv/environment.hh: New files.
* src/ltlparse/public.hh (parse): Take an environment as third
argument.
* src/ltlparse/ltlparse.yy (ATOMIC_PROP, parse): Require the
atomic proposition via the environment.
* src/ltltest/readltl.cc (main): Adjust the call to parse().
* src/ltltest/Makefile.am (LDADD): Add ../ltlenv/libltlenv.a.

* src/ltlvisit/Makefile.am (libltlvisit_a_SOURCES): Add them.
* src/ltltest/equals.cc (main) [NENOFORM]: Call negative_normal_form.
* src/ltltest/nenoform.test, src/ltltest/tunenoform.test: New files.
* src/ltltest/Makefile.am (check_PROGRAMS): Add nenoform and
tunenoform.
(nenoform_SOURCES, nenoform_CPPFLAGS, tunenoform_SOURCES,
tunenoform_CPPFLAGS): New variables.
(TESTS): Add nenoform.test and tunenoform.test.

* src/ltlvisit/Makefile.am (libltlvisit_a_SOURCES): Add them.
* src/ltltest/tunabbrev.test: New file.
* src/ltltest/lunabbrev.test: Fix comment.
* src/ltltest/Makefile.am (TESTS): Add tunabbrev.test.
(check_PROGRAMS): Add tunabbrev.
(tunabbrev_SOURCES, tunabbrev_CPPFLAGS): New variables.
* src/ltltest/equals.cc (main) [TUNABBREV]: Call unabbreviate_ltl.
* src/ltlvisit/lunabbrev.hh (unabbreviate_logic_visitor::recurse):
New virtual function.
* src/ltlvisit/lunabbrev.cc (unabbreviate_logic_visitor::recurse):
Likewise.
(unabbreviate_logic_visitor::visit): Use it instead of calling
unabbreviate_logic directly.

* src/ltlvisit/Makefile.am (libltlvisit_a_SOURCES): Add them.
* src/ltlast/multop.cc (multop::multop(type)): New constructor.
* src/ltlast/multop.hh (multop::multop(type)): New constructor.
* src/ltltest/lunabbrev.test: New file.
* src/ltltest/Makefile.am (TESTS): Add lunabbrev.test.
(check_PROGRAMS): Add lunabbrev.
(lunabbrev_SOURCES, lunabbrev_CPPFLAGS): New variables.
* src/ltltest/equals.cc (main) [LUNABBREV]: Call unabbreviate_logic.

* src/ltlvisit/Makefile.am (libltlvisit_a_SOURCES): Add equals.hh
and equals.cc.
* src/ltltest/equals.cc, src/ltltest/equals.test: New files.
* src/ltltest/Makefile.am (check_PROGRAMS): Add equals.
(equals_SOURCES): New variable.
(TESTS): Add equals.test.

src/Makefile.am, src/ltlast/Makefile.am, src/ltlast/allnodes.hh,
src/ltlast/atomic_prop.cc, src/ltlast/atomic_prop.hh,
src/ltlast/binop.cc, src/ltlast/binop.hh, src/ltlast/constant.cc,
src/ltlast/constant.hh, src/ltlast/formulae.hh,
src/ltlast/multop.cc, src/ltlast/multop.hh, src/ltlast/predecl.hh,
src/ltlast/unop.cc, src/ltlast/unop.hh, src/ltlast/visitor.hh,
src/ltlparse/Makefile.am, src/ltlparse/ltlparse.yy,
src/ltlparse/ltlscan.ll, src/ltlparse/parsedecl.hh,
src/ltlparse/public.hh, src/ltlvisit/Makefile.am,
src/ltlvisit/dotty.cc, src/ltlvisit/dotty.hh,
src/ltlvisit/dump.cc, src/ltlvisit/dump.hh,
src/ltlvisit/rewrite.cc, src/ltlvisit/rewrite.hh,
src/ltltest/Makefile.am, src/ltltest/defs.in, src/ltltest/readltl.cc,
src/ltltest/parse.test, src/ltltest/parseerr.test,
src/misc/Makefile.am, src/misc/const_sel.hh: New files.