I want there to be a box under the bed, but Inform apparently doesn’t.
[code]A bed is a supporter in Bedroom.
A box is under the bed. It is a container.[/code]
Result:
Problem. The sentence ‘A box is under the bed’ appears to say two things are the same - I am reading ‘box’ and ‘under the bed’ as two different things, and therefore it makes no sense to say that one is the other: it would be like saying that ‘John is Paul’. It would be all right if the second thing were the name of a kind, perhaps with properties: for instance ‘Abbey Road is a lighted room’ says that something called Abbey Road exists and that it is a ‘room’, which is a kind I know about, combined with a property called ‘lighted’ which I also know about.
Instead of searching the bed when the box is out of play:
say "You find a box under the bed!"
move the box to the location.
I think “look under bed” would trigger “search bed”, but if not, you can add a grammar rule for that.
Understand "look under [something]" as searching.
Untested code, but something like that should work.
You want the extension Hiding Under by Eric Eve. Or just Underside. Both are in the Public Library, so your IDE should be able to download them. (Do not under any circumstances attempt to download extensions from the inform7.com website.)