Given that sk/pk/k are now hardcoded, we can exploit their occurrences with this
new heuristic.
The heuristic can now scan for the lowest term depth at which either sk or k occur.
This will cause the heuristic to favor looking for sk, then sk(x), and only later
other terms. In a small test this was twice as fast. For protocols based on pk only
the performance loss should be negligible.
The old heuristic was 162, now it is 162+512 = 674.
In the near future, the default exit code behavior should be made obsolete anyway,
as the exit codes are not a nice way to report status.
It used to be convenient for shell scripting in early times,
when the parallel tests were run using the forward model
checker, but no modern script should be relying on it.
When untyped variables occur, the encryption level depth pruning is for
now unjustified. Maybe we can get a proof later. Previously this was
hidden, which was a bad design decision. Now the output is much
clearer.
This cleans up some graphs rather nicely. There is only one potential
drawback (not observed in practive):
If two bindings have the same from/to, but different interpretations,
we might lose information. In particular the 'select' intermediate nodes might
pose a problem and we would be better off by not having any interpretation on
what is selected.
This switch was previously known as '--state-space', but the new name is
much better.
Backwards compatibility:
'-c' was previously used by '--check', so check is now abbreviated to
'-C'.
'-s,--state-space' still works but is from now on considered to be
deprecated.
I've added a marked for the Athena problem case, and now no more false 'complete proof' results are produced.
However, the tool reports, 'no attack within bounds', which is slightly inaccurate
depending on the interpretatio of 'bounds'.
The old version numbers were retrieved from SVN; of course this no longer works. Now no versions are retrieved on normal building. Instead, this is covered by the dist building script.
