Scottish Café
The Scottish Café () was a café in Lwów, Poland (now Lviv, Ukraine) where, in the 1930s and 1940s, mathematicians from the Lwów School of Mathematics collaboratively discussed research problems, particularly in functional analysis and topology. Stanisław Ulam recounts that the tables of the café had marble tops, so they could write in pencil, directly on the table, during their discussions. To keep the results from being lost, and after becoming annoyed with their writing directly on the table tops, Stefan Banach's wife provided the mathematicians with a large notebook, which was used for writing the problems and  answers and eventually became known as the "Scottish Book". The book—a collection of solved, unsolved, and even probably unsolvable problems—could be borrowed by any of the guests of the café. Solving any of the problems was rewarded with prizes, with the most difficult and challenging problems having expensive prizes (during the Great Depression and on the eve of World War II), such as a bottle of fine brandy. For problem 153, which was later recognized as being closely related to Stefan Banach's "basis problem", Stanisław Mazur offered the prize of a live goose. This problem was solved  only in 1972 by Per Enflo, who was presented with the live goose in a ceremony that was broadcast throughout Poland. The café building now houses the Szkocka Restaurant & Bar (named for the original Scottish Café) and the Atlas Deluxe hotel at the street address of 27 Taras Shevchenko Prospekt. See also. The following mathematicians were associated with the Lwów School of Mathematics or contributed to "The Scottish Book":