Medium of exchange was observed as early as Oresme, Copernicus and then in 1558 by Sir Thomas Gresham, that bad money drives out good in any marketplace (Gresham's Law states "Where legal tender laws exist, bad money drives out good money"). A more precise definition is this: "A currency that is artificially overvalued by law will drive out of circulation a currency that is artificially undervalued by that law." Gresham's law is therefore a specific application of the general law of price controls. A common explanation is that people will always keep the less adultered, less clipped, sweated, less filed, less trimmed coin,
Alexander and the Terrible, Horrible, No Good, Very Bad Day and the cat says he wants to sleep with Anthony (but not Alexander). In the end, Alexander says it has been a terrible, horrible, no good very bad day for him. His mother says to him that some days are like that, even in Australia. A running gag throughout the book is Alexander repeating several times that he wants to move to Australia because he thinks it is better there. It ends with his mother's assurance that everybody has bad days, even those who live there. In the Australian and New Zealand versions, he wants to move to Timbuktu instead.