Hi,

When invoking `autfilt sub.aut --included-in=sup.aut` on the two enclosed Buchi automata
with Spot 2.10 I am getting:

```

Too many acceptance sets used.  The limit is 32.

```

With Spot 2.9.7 I was getting a non-terminating execution.

Is it the expected result? If so, what is the explanation behind the too many acceptance sets?

Is it the complementation procedure for `sup.aut` that fails?

Thank you and keep up with the excellent work,

Pierre.