Reported by Florian Renkin.
* spot/twaalgos/cleanacc.cc: Do not rewrite
...Fin(0)&(Fin(1)|(Fin(3)&Inf(4)))... as Fin(0)&f when it appears that
{1,3} cannot receive {0}, because {1} is used elsewhere in the
acceptance.
* tests/python/simplacc.py: Add test case.