("cat" OR "dog") NOT ("cat" AND "dog")

indeed............ camaleons etc etc

Well, that is not a problem, because the author really had mentioned the words "doc" and "cat" on the keywords.

But that search fails, because logically a document where both words occur, should not appear on search results.

One should have got documents where "cat" mentioned alone, and documents where "dog" mentioned alone, and no documents where both mentioned.

ahhh ok

;-)))))))))))
I would like to call this picture extraordinary - in short XOR ;-)

Yes, that is a very fitting title as well =D

Looks like the representation of an arithmetical problem in set theory.
What is the intersection of a dog and a cat? A cag, or a dot? ;-))

God?

Found! st.depositphotos.com/1636517/1604/i/950/depositphotos_16041941-stock-photo-dog-is-tempted-by-cat.jpg

Wow! This is very brave of the cat, considering that the dog has an accelerator! ;-))

And did you notice the intersection? ;-)

ahhhhh
mathematics again
(Boolean operators)
;-)

Or information retrieval ;-)

No intersection!