* src/tgba/bddprint.cc (bdd_format_set): Likewise.
* src/tgba/state.hh: Add Doxygen comments.
(state::compare): Take a state*, not a state&.
(state_ptr_less_than): New functor.
* src/tgba/statebdd.hh (state_bdd::compare): Take a state*, not a
state&.
* src/tgba/statebdd.cc (state_bdd::compare): Likewise.
* src/tgba/succiter.hh: Add Doxygen comments.
* src/tgba/tgba.hh: Mention promises.
(tgba::formate_state): New pure virtual method.
* src/tgba/tgbabddconcrete.hh (tgba_bdd_concrete::formate_state):
New method.
* src/tgba/tgbabddconcrete.cc (tgba_bdd_concrete::formate_state):
Likewise.
* src/tgbaalgos/dotty.cc: Adjust to use state_ptr_less_than
and tgba::formate_state.