安徒生有一则名为《老头子总是不会错》的童话故事:一天,一对清贫的乡村老夫妇想把家中唯一值钱的一匹马拉到市场上去换点更有用的东西。老头子牵着马去了,他先与人换得一头母牛,又用母牛换了一只羊,再用羊换来一只肥鹅,鹅又换了母鸡,最后把母鸡换成了一袋烂苹果。在每次交换中 Andersen had a fairy tale called “The Old Man Always Wrong”: One day a poor old couple in the country wanted to bring the only valuable horse in the house to the market for something more useful. The old man led the horse, he first exchanged a cow with others, but also with a cow for a sheep, then goose in exchange for a fat goose, goose and hen, and finally replaced the hen A bag of rotten apples. In every exchange