Peter McLaughlin’s Reviews > Notes on the Theory of Choice > Status Update

Extremely like me to get stumped by literally the very first exercise in the very first chapter. Misunderstood the question initially and kept banging my head against a wall trying to prove something that (I have since learned) is not true. When I figured out my mistake, I managed to prove the correct thing, but only by bringing in some real analysis—which can't be what Kreps intended?