Otis Gospodnetic writes:
> Redirecting to lucene-user....
> 
> --- Jim Hargrave <[EMAIL PROTECTED]> wrote:
> > Can anyone tell me why these two queries would produce different
> > results:
> >  
> > +A -B
> >  
> > A -(-B) 
> 
> A and +A are not the same thing when you have multiple terms in a
> query.
> 
Hmm. As far as I understood boolean queries so far
a -b and +a -b 
should be the same (while a b -c and +a +b -c are different of course).

a -(-b) on the other side contains a boolean query only searching for -b.
Lucene can not handle this type of query. I'm not sure what happens in this
case. But AFAIK you should never use a boolean query containing only 
prohibited terms in a query. 
If I test this, I don't get any results for a -(-b) and the same result
for 'a' and 'a +(-b)'.
The query parser patch I added yesterday to bugzilla, drops such queries.

> > Also, we are having a hard time understanding why the Query parser
> > takes this
> > query: "A AND NOT B" and returns this "+A +(-B)". Shouldn't this be
> > "+A -B"?
> 
a AND NOT b IS parsed to +a -b by lucenes standard query parser.
Don't know where you found +a +(-b).

+a +(-b) would be wrong in the above sense.

Morus

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