- Liechtenstein (Wikipedia)
Liechtenstein (/ˈlɪktənstaɪn/, LIK-tən-styne; German: [ˈlɪçtn̩ʃtaɪn]), officially the Principality of Liechtenstein (German: Fürstentum Liechtenstein, [ˈfʏʁstn̩tuːm ˈlɪçtn̩ˌʃtaɪ̯n]), is a doubly landlocked German-speaking microstate in the Central European Alps, between Austria in the east and north and Switzerland in the west and south. Liechtenstein is a semi-constitutional monarchy headed by the prince of Liechtenstein of the House of Liechtenstein, currently led by Hans-Adam II. It is Europe’s fourth-smallest country, with an area of just over 160 square kilometres (62 square miles) and a population of 40,023. It is the world’s smallest country to border two countries, and is one of the few countries with no debt.
- Barber paradox (Wikipedia)
The barber paradox is a puzzle derived from Russell’s paradox. It was used by Bertrand Russell as an illustration of the paradox, though he attributes it to an unnamed person who suggested it to him. The puzzle shows that an apparently plausible scenario is logically impossible. Specifically, it describes a barber who is defined such that he both shaves himself and does not shave himself, which implies that no such barber exists.