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Józef Schreier
Józef Schreier (; 18 February 1909, Drohobycz, Austria-Hungary – April 1943, Drohobycz, Occupied Poland) was a Polish mathematician of Jewish origin, known for his work in functional analysis, group theory and combinatorics. He was a member of the Lwów School of Mathematics and a victim of the Holocaust. Józef Schreier was born on 18 February 1909 in Drohobycz. His father was a rabbi and doctor of philosophy. His cousin was the musician Alfred Schreyer. From 1927-31 he studied at the Jan Kazimierz University in Lwów. In his first published paper, he defined what later came to be known as Schreier sets in order to show that not all Banach spaces possess the weak Banach-Saks property, disproving a conjecture of Stefan Banach and Stanisław Saks. Schreier sets were later discovered independently by researchers in Ramsey theory. Schreier completed his master's degree ''On tournament elimination systems'' in 1932 under the direction of Hugo Steinhaus. Schreier correctly ...
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Josef Schreier
Josef may refer to *Josef (given name) *Josef (surname) * ''Josef'' (film), a 2011 Croatian war film *Musik Josef Musik Josef is a Japanese manufacturer of musical instruments. It was founded by Yukio Nakamura, and is the only company in Japan specializing in producing oboe The oboe ( ) is a type of double reed woodwind instrument. Oboes are usually ma ...
, a Japanese manufacturer of musical instruments {{disambiguation ...
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Schreier Set
Schreier is a surname of German origin. Notable people with the surname include: *Christian Schreier (born 1959), German footballer *Dan Moses Schreier, American sound designer and composer *Jake Schreier, American director *Józef Schreier, Polish mathematician *Otto Schreier (1901-1929), Austrian mathematician *Peter Schreier (1935–2019), German tenor and conductor *Richard Schreier, Canadian engineer *Sandy Schreier, American fashion historian and collector *Jason Schreier, American journalist and author See also * Schreyer * Shrayer Shrayer is a surname. Notable people with the surname include: * David Shrayer-Petrov (born 1936), Russian American novelist, poet, memoirist, translator and medical scientist * Maxim D. Shrayer (born 1967), Russian-American author, translator, an ... * Shroyer, Pennsylvania German form * Shrier, Americanized version {{surname German-language surnames ...
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Semigroups
In mathematics, a semigroup is an algebraic structure consisting of a set together with an associative internal binary operation on it. The binary operation of a semigroup is most often denoted multiplicatively: ''x''·''y'', or simply ''xy'', denotes the result of applying the semigroup operation to the ordered pair . Associativity is formally expressed as that for all ''x'', ''y'' and ''z'' in the semigroup. Semigroups may be considered a special case of magmas, where the operation is associative, or as a generalization of groups, without requiring the existence of an identity element or inverses. The closure axiom is implied by the definition of a binary operation on a set. Some authors thus omit it and specify three axioms for a group and only one axiom (associativity) for a semigroup. As in the case of groups or magmas, the semigroup operation need not be commutative, so ''x''·''y'' is not necessarily equal to ''y''·''x''; a well-known example of an operation that is ass ...
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Scottish Café
The Scottish Café ( pl, Kawiarnia Szkocka) 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 Gre ...
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Federation Of American Scientists
The Federation of American Scientists (FAS) is an American nonprofit global policy think tank with the stated intent of using science and scientific analysis to attempt to make the world more secure. FAS was founded in 1946 by scientists who worked on the Manhattan Project to develop the first atomic bombs. The Federation of American Scientists aims to reduce the amount of nuclear weapons that are in use, and prevent nuclear and radiological terrorism. They hope to present high standards for nuclear energy's safety and security, illuminate government secrecy practices, as well as track and eliminate the global illicit trade of conventional, nuclear, biological and chemical weapons. With 100 sponsors, the Federation of American Scientists says that it promotes a safer and more secure world by developing and advancing solutions to important science and technology security policy problems by educating the public and policy makers, and promoting transparency through research and ana ...
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Stanisław Ulam
Stanisław Marcin Ulam (; 13 April 1909 – 13 May 1984) was a Polish-American scientist in the fields of mathematics and nuclear physics. He participated in the Manhattan Project, originated the Teller–Ulam design of thermonuclear weapons, discovered the concept of the cellular automaton, invented the Monte Carlo method of computation, and suggested nuclear pulse propulsion. In pure and applied mathematics, he proved some theorems and proposed several conjectures. Born into a wealthy Polish Jewish family, Ulam studied mathematics at the Lwów Polytechnic Institute, where he earned his PhD in 1933 under the supervision of Kazimierz Kuratowski and Włodzimierz Stożek. In 1935, John von Neumann, whom Ulam had met in Warsaw, invited him to come to the Institute for Advanced Study in Princeton, New Jersey, for a few months. From 1936 to 1939, he spent summers in Poland and academic years at Harvard University in Cambridge, Massachusetts, where he worked to establish import ...
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Blindfold Chess
Blindfold chess, also known as ''sans voir'', is a form of chess play wherein the players do not see the positions of the pieces and do not touch them. This forces players to maintain a mental model of the positions of the pieces. Moves are communicated via a recognized chess notation. Blindfold chess was considered miraculous for centuries but now there is greater recognition of people who can keep track of more than one simultaneous blindfolded game. In simultaneous blindfold play, an intermediary usually relays the moves between the players. Early history Blindfold chess was first played quite early on in the history of chess, with perhaps the first game being played by Sa'id bin Jubair (665–714) in the Middle East. In Europe, playing chess blindfolded became popular as a means of handicapping a chess master when facing a weaker opponent, or of simply displaying one's superior abilities. H. J. R. Murray in his book ''A History of Chess'' recorded another type of ...
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Hugo Steinhaus
Hugo Dyonizy Steinhaus ( ; ; January 14, 1887 – February 25, 1972) was a Polish mathematician and educator. Steinhaus obtained his PhD under David Hilbert at Göttingen University in 1911 and later became a professor at the Jan Kazimierz University in Lwów (now Lviv, Ukraine), where he helped establish what later became known as the Lwów School of Mathematics. He is credited with "discovering" mathematician Stefan Banach, with whom he gave a notable contribution to functional analysis through the Banach–Steinhaus theorem. After World War II Steinhaus played an important part in the establishment of the mathematics department at Wrocław University and in the revival of Polish mathematics from the destruction of the war. Author of around 170 scientific articles and books, Steinhaus has left his legacy and contribution in many branches of mathematics, such as functional analysis, geometry, mathematical logic, and trigonometry. Notably he is regarded as one of the early found ...
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Ramsey Theory
Ramsey theory, named after the British mathematician and philosopher Frank P. Ramsey, is a branch of mathematics that focuses on the appearance of order in a substructure given a structure of a known size. Problems in Ramsey theory typically ask a question of the form: "how big must some structure be to guarantee that a particular property holds?" More specifically, Ron Graham described Ramsey theory as a "branch of combinatorics". Examples A typical result in Ramsey theory starts with some mathematical structure that is then cut into pieces. How big must the original structure be in order to ensure that at least one of the pieces has a given interesting property? This idea can be defined as partition regularity. For example, consider a complete graph of order ''n''; that is, there are ''n'' vertices and each vertex is connected to every other vertex by an edge. A complete graph of order 3 is called a triangle. Now colour each edge either red or blue. How large must ''n'' be in ...
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