(tgba_bdd_concrete_factory::~tgba_bdd_concrete_factory): destroy the
formulae used as keys in prom_.
(tgba_bdd_concrete_factory::create_promise): Delete.
(tgba_bdd_concrete_factory::declare_promise,
tgba_bdd_concrete_factory::finish): New functions.
* src/tgba/tgbabddconcretefactory.hh
(tgba_bdd_concrete_factory::create_promise): Delete.
(tgba_bdd_concrete_factory::declare_promise,
tgba_bdd_concrete_factory::finish): New functions.
(tgba_bdd_concrete_factory::prom_): New map.
* src/tgba/ltl2tgba.cc (ltl_trad_visitor::visit): Adjust
the Fx and aUb cases to register promises with
tgba_bdd_concrete_factory::declare_promise().
(ltl2tgba): Call tgba_bdd_concrete_factory::finish().