Later, a full-force Bear Patrol is on watch. Homer watches proudly.
Homer: Not a bear in sight. The Bear Patrol must be working like a
Lisa: That's spacious reasoning, Dad.
Homer: Thank you, dear.
Lisa: By your logic I could claim that this rock keeps tigers away.
Homer: Oh, how does it work?
Lisa: It doesn't work.
Lisa: It's just a stupid rock.
Lisa: But I don't see any tigers around, do you?
[Homer thinks of this, then pulls out some money]
Homer: Lisa, I want to buy your rock.