The config file parser seems to accept only an undefined (and weird)
subset of the documented grammar. Examples:

It accepts
 not user "foo" or not exe "bar"
but not
 not (user "foo" and exe "bar")
nor
 not ((user "foo") and (exe "bar"))
nor
 not ( user "foo" and exe "bar )
. It accepts
 user "foo"
 exe "bar"
but not
 exe "bar"
 user "foo"
. It accepts
 user "foo" and exe "bar"
but not
 exe "bar" and user "foo"
.

That makes it rather difficult writing rules files with guessing what
it will accept and what not.

I've tried to reach the upstream for this package and he seems
unreachable. The plans for a version 2.0 (which would solve the parsing
problem) are now, IMHO, in the void.

I'm tagging this as wontfix.

[]s

Pablo