- published: 09 Aug 2015
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In predicate logic, an existential quantification is the predication of a property or relation to at least one member of the domain. It is denoted by the logical operator symbol ∃ (pronounced "there exists" or "for some"), which is called the existential quantifier. Existential quantification is distinct from universal quantification ("for all"), which asserts that the property or relation holds for any members of the domain.
Symbols are encoded U+2203 ∃ there exists (HTML: ∃
∃
as a mathematical symbol) and U+2204 ∄ there does not exist (HTML: ∄
).
Consider a formula that states that some natural number multiplied by itself is 25.
0·0 = 25, or 1·1 = 25, or 2·2 = 25, or 3·3 = 25, and so on.
This would seem to be a logical disjunction because of the repeated use of "or". However, the "and so on" makes this impossible to integrate and to interpret as a disjunction in formal logic. Instead, the statement could be rephrased more formally as
For some natural number n, n·n = 25.
This is a single statement using existential quantification.
Avram Noam Chomsky (/ˈnoʊm ˈtʃɒmski/; born December 7, 1928) is an American linguist, philosopher,cognitive scientist, historian, and activist. He is an Institute Professor and Professor (Emeritus) in the Department of Linguistics & Philosophy at MIT, where he has worked for over 50 years. Chomsky has been described as the "father of modern linguistics" and a major figure of analytic philosophy. His work has influenced fields such as computer science, mathematics, and psychology.
Ideologically identifying with anarcho-syndicalism and libertarian socialism, Chomsky is known for his critiques of U.S. foreign policy and contemporary capitalism, and he has been described as a prominent cultural figure. His media criticism has included Manufacturing Consent: The Political Economy of the Mass Media (1988), co-written with Edward S. Herman, an analysis articulating the propaganda model theory for examining the media.
According to the Arts and Humanities Citation Index in 1992, Chomsky was cited as a source more often than any other living scholar from 1980 to 1992, and was the eighth most cited source overall. Chomsky is the author of over 100 books. He is credited as the creator or co-creator of the Chomsky hierarchy, the universal grammar theory, and the Chomsky–Schützenberger theorem.
Mr. Bean is a British comedy television programme series of 14 half-hour episodes written by and starring Rowan Atkinson as the title character. Different episodes were also written by Robin Driscoll, Richard Curtis and one by Ben Elton. The pilot episode was broadcast on ITV on 1 January 1990, with the last television episode, "Goodnight Mr. Bean" broadcast on 31 October 1995. The final episode, "Hair by Mr. Bean of London", was a video exclusive released on 15 November 1995, but not broadcast in the UK until 2006.
Based on a character originally developed by Atkinson while he was studying for his master's degree at Oxford University, the series follows the exploits of Mr. Bean, described by Atkinson as "a child in a grown man's body", in solving various problems presented by everyday tasks and often causing disruption in the process. Bean rarely speaks, and the largely physical humour of the series is derived from his interactions with other people and his unusual solutions to situations. The series was influenced by physical performers such as Jacques Tati and comic actors from silent films.