Thank you Alexandre! I've played a bit with it and here is an observation. If there is no `States: ` header in the file then all the numbers are computed based on the states listed in the body. However if there is a `States: ` header then things are a bit different. Warnings (many of them) will be displayed if, in the body, there are more states than the number declared in the header. In that case the total number `%[a]s` computed is the same as if the `States: ` header was absent. If, in the body, there are less states than the number declared in the `States: ` header then the number of unreachable states will be "increased" so that the equality `%[r]s + %[u]s = %[a]s` holds. This behavior is consistent with the output of `--hoaf` which is "padding" the body part by declaring all these unreachable states explicitly. On the other hand, `jhoafparser parse` returns a warning: `Warning: There are <number> states without definition` However `jhoafparser print` performs no padding unlike `autfilt --hoaf`. I realize I might be the only one who got confused about this corner case. If there is somebody else then we now have a record in the mailing list. Perhaps the same warning should be output by `autfilt` so that the user knows something is going on when looking at `%[a]s`. Pierre. On Fri, 21 Oct 2022 at 17:37, Alexandre Duret-Lutz &lt;adl(a)lrde.epita.fr&gt; wrote: