Yes and yes.
Edson
PS: it is not that difficult... ;)
2008/4/8 Dirk Bergstrom <dirk(a)juniper.net>:
I want to write a rule that says "Find all long-eared dogs that
do not
have
short, black hair". This seems like the simple way to do it:
collect( Dog( ears=="long", not (hair=="short" &&
color=="black") )
But that doesn't parse. Some digging through the archives unearthed a
mention
of De Morgan's laws, which leads to:
http://en.wikipedia.org/wiki/De_Morgan's_laws<http://en.wikipedia....
Which explains that I can instead write:
collect( Dog( ears=="long", (hair!="short" ||
color!="black") )
Which, after some mental effort, turns out to be the right thing.
However, had I not found the reference to De Morgan's Law, it would have
taken
me a long time to get there (if indeed I ever would have). The end result
is
also quite difficult to parse if you're not a logician, and thus not very
user-friendly.
Does anyone think it would be worthwhile to open a Jira requesting the
ability
to negate a constraint group? And, if I did open such a thing, do the
developers think it would be reasonably easy to implement?
--
Dirk Bergstrom dirk(a)juniper.net
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Edson Tirelli
JBoss Drools Core Development
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