1. entering 'invisible marmalade teapot' and getting no results
2. changing to 'invisible marmalade teapot with tartan cosy', again nothing
3. so 'invisible marmalade teapot with tartan cosy in outer space', ditto
you get the idea...? it's just like in the real world, when you might go to a bookshop and say You: do you have that new crime novel in stock?
Bookseller: er, i don't know which one you mean?
Y: the new crime novel by john grisham, pelican something or other?
B: oh, right, yes, here it is!
and everyone is happy.default OR in a search engine would mean my first example eventually starting to return results about transparent space coffee pots with tartan cosies, ignoring the first few terms but the rest match, which is often helpful, particularly if you're doing an exploratory search for something where you aren't sure of the exact details.
I don't find your examples compelling.
If you want to do an additional search that does not depend on your first terms, you simply bring up a new search window.
In your 'real world' example, the equivalent search queries would go something like
search: new crime novel
result: way way too much stuff
search: new crime novel john grisham pelican
result: exactly the right book because every one of those terms applies