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Martin Davis (mathematician)
Martin David Davis (March 8, 1928 – January 1, 2023) was an American mathematician, known for his work on Hilbert's tenth problem.. Biography Davis's parents were Jewish immigrants to the US from Łódź, Poland, and married after they met again in New York City. Davis grew up in the Bronx, where his parents encouraged him to obtain a full education. Davis received his Ph.D. from Princeton University in 1950, where his advisor was Alonzo Church. During a research instructorship at the University of Illinois at Urbana-Champaign in the early 1950s, he joined the ''Control Systems Lab'' and became one of the early programmers of the ORDVAC. He was Professor Emeritus at New York University. Davis died on January 1, 2023, at the age of 94. Contributions Davis was the co-inventor of the Davis–Putnam algorithm and the DPLL algorithms. He is also known for his model of Post–Turing machines, and his work on Hilbert's tenth problem leading to the MRDP theorem. Awards and honors In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York City
New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the List of United States cities by population density, most densely populated major city in the United States, and is more than twice as populous as second-place Los Angeles. New York City lies at the southern tip of New York (state), New York State, and constitutes the geographical and demographic center of both the Northeast megalopolis and the New York metropolitan area, the largest metropolitan area in the world by urban area, urban landmass. With over 20.1 million people in its metropolitan statistical area and 23.5 million in its combined statistical area as of 2020, New York is one of the world's most populous Megacity, megacities, and over 58 million people live within of the city. New York City is a global city, global Culture of New ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronx
The Bronx () is a borough of New York City, coextensive with Bronx County, in the state of New York. It is south of Westchester County; north and east of the New York City borough of Manhattan, across the Harlem River; and north of the New York City borough of Queens, across the East River. The Bronx has a land area of and a population of 1,472,654 in the 2020 census. If each borough were ranked as a city, the Bronx would rank as the ninth-most-populous in the U.S. Of the five boroughs, it has the fourth-largest area, fourth-highest population, and third-highest population density.New York State Department of Health''Population, Land Area, and Population Density by County, New York State – 2010'' retrieved on August 8, 2015. It is the only borough of New York City not primarily on an island. With a population that is 54.8% Hispanic as of 2020, it is the only majority-Hispanic county in the Northeastern United States and the fourth-most-populous nationwide. The Bronx ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Influence Of Non-standard Analysis
Abraham Robinson's theory of nonstandard analysis has been applied in a number of fields. Probability theory "Radically elementary probability theory" of Edward Nelson combines the discrete and the continuous theory through the infinitesimal approach. The model-theoretical approach of nonstandard analysis together with Loeb measure theory allows one to define Brownian motion as a hyperfinite random walk, obviating the need for cumbersome measure-theoretic developments. Jerome Keisler used this classical approach of nonstandard analysis to characterize general stochastic processes as hyperfinite ones. Economics Economists have used nonstandard analysis to model markets with large numbers of agents (see Robert M. Anderson (economist)). Education An article by Michèle Artigue concerns the teaching of analysis. Artigue devotes a section, "The non standard analysis and its weak impact on education" on page 172, to non-standard analysis. She writes: :The non-standard analysis re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halting Problem
In computability theory, the halting problem is the problem of determining, from a description of an arbitrary computer program and an input, whether the program will finish running, or continue to run forever. Alan Turing proved in 1936 that a general algorithm to solve the halting problem for all possible program–input pairs cannot exist. For any program that might determine whether programs halt, a "pathological" program , called with some input, can pass its own source and its input to ''f'' and then specifically do the opposite of what ''f'' predicts ''g'' will do. No ''f'' can exist that handles this case. A key part of the proof is a mathematical definition of a computer and program, which is known as a Turing machine; the halting problem is '' undecidable'' over Turing machines. It is one of the first cases of decision problems proven to be unsolvable. This proof is significant to practical computing efforts, defining a class of applications which no programming inventi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Criticism Of Non-standard Analysis
Nonstandard analysis and its offshoot, nonstandard calculus, have been criticized by several authors, notably Errett Bishop, Paul Halmos, and Alain Connes. These criticisms are analyzed below. Introduction The evaluation of nonstandard analysis in the literature has varied greatly. Paul Halmos described it as a technical special development in mathematical logic. Terence Tao summed up the advantage of the hyperreal framework by noting that it The nature of the criticisms is not directly related to the logical status of the results proved using nonstandard analysis. In terms of conventional mathematical foundations in classical logic, such results are quite acceptable. Abraham Robinson's nonstandard analysis does not need any axioms beyond Zermelo–Fraenkel set theory (ZFC) (as shown explicitly by Wilhelmus Luxemburg's ultrapower construction of the hyperreals), while its variant by Edward Nelson, known as internal set theory, is similarly a conservative extension of ZFC. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Academy Of Arts And Sciences
The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other Founding Fathers of the United States. It is headquartered in Cambridge, Massachusetts. Membership in the academy is achieved through a thorough petition, review, and election process. The academy's quarterly journal, ''Dædalus'', is published by MIT Press on behalf of the academy. The academy also conducts multidisciplinary public policy research. History The Academy was established by the Massachusetts legislature on May 4, 1780, charted in order "to cultivate every art and science which may tend to advance the interest, honor, dignity, and happiness of a free, independent, and virtuous people." The sixty-two incorporating fellows represented varying interests and high standing in the political, professional, and commercial secto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fellow
A fellow is a concept whose exact meaning depends on context. In learned or professional societies, it refers to a privileged member who is specially elected in recognition of their work and achievements. Within the context of higher educational institutions, a fellow can be a member of a highly ranked group of teachers at a particular college or university or a member of the governing body in some universities (such as the Fellows of Harvard College); it can also be a specially selected postgraduate student who has been appointed to a post (called a fellowship) granting a stipend, research facilities and other privileges for a fixed period (usually one year or more) in order to undertake some advanced study or research, often in return for teaching services. In the context of research and development-intensive large companies or corporations, the title "fellow" is sometimes given to a small number of senior scientists and engineers. In the context of medical education in No ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lester R
Lester is an ancient Anglo-Saxon surname and given name. Notable people and characters with the name include: People Given name * Lester Bangs (1948–1982), American music critic * Lester W. Bentley (1908–1972), American artist from Wisconsin * Lester Bird (1938–2021), second prime minister of Antigua and Barbuda (1994–2004) * Lester Cotton (born 1996), American football player * Lester del Rey (1915–1993), American science fiction author and editor * Lester Flatt (1914–1979), American bluegrass musician * Lester Gillis (1908–1934), better known as Baby Face Nelson, American gangster * Lester Holt (born 1959), American television journalist * Lester Charles King (1907–1989), English geomorphologist * Lester Lanin (1907–2004), American jazz and pop music bandleader * Lester Lockett (1912–2005), American Negro League baseball player * Lester Maddox (1915–2003), governor and lieutenant governor of the U.S. state of Georgia * Lester Patrick (1883–1960), Can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reuben Hersh
Reuben Hersh (December 9, 1927 – January 3, 2020) was an American mathematician and academic, best known for his writings on the nature, practice, and social impact of mathematics. Although he was generally known as Reuben Hersh, late in life he sometimes used the name Reuben Laznovsky in recognition of his father's ancestral family name. His work challenges and complements mainstream philosophy of mathematics. Education After receiving a B.A. in English literature from Harvard University in 1946, Hersh spent a decade writing for ''Scientific American'' and working as a machinist. After losing his right thumb when working with a band saw, he decided to study mathematics at the Courant Institute of Mathematical Sciences. In 1962, he was awarded a Ph.D. in mathematics from New York University; his advisor was Peter Lax, P.D. Lax. He was affiliated with the University of New Mexico since 1964, where he was professor emeritus. Academic career Hersh wrote a number of technical a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leroy P
Leroy or Le Roy may refer to: People * Leroy (name), a given name and surname * Leroy (musician), American musician * Leroy (sailor), French sailor Places United States * Leroy, Alabama * Le Roy, Illinois * Le Roy, Iowa * Le Roy, Kansas * Le Roy, Michigan * Le Roy, Minnesota * Le Roy (town), New York ** Le Roy (village), New York * Leroy, Indiana * Leroy, Texas * LeRoy, Wisconsin, a town * LeRoy (community), Wisconsin, an unincorporated community * Leroy Township, Calhoun County, Michigan * Leroy Township, Ingham County, Michigan * LeRoy Township, Lake County, Ohio * Leroy Township, Pennsylvania * LeRoy, West Virginia Elsewhere * Leroy, Saskatchewan, Canada * Rural Municipality of Leroy No. 339, Saskatchewan, Canada * 93102 Leroy, an asteroid Arts and entertainment * ''Leroy'' (film), a 2007 German comedy film * Leroy (''Lilo & Stitch''), a character in ''Leroy & Stitch'' * Leroy (''South Park''), a ''South Park'' character * "Leroy", a 1958 song by Jack Scott Other us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diophantine Set
In mathematics, a Diophantine equation is an equation of the form ''P''(''x''1, ..., ''x''''j'', ''y''1, ..., ''y''''k'') = 0 (usually abbreviated ''P''(', ') = 0) where ''P''(', ') is a polynomial with integer coefficients, where ''x''1, ..., ''x''''j'' indicate parameters and ''y''1, ..., ''y''''k'' indicate unknowns. A Diophantine set is a subset ''S'' of \mathbb^j, the set of all ''j''-tuples of natural numbers, so that for some Diophantine equation ''P''(', ') = 0, :\bar \in S \iff (\exists \bar \in \mathbb^)(P(\bar,\bar)=0) . That is, a parameter value is in the Diophantine set ''S'' if and only if the associated Diophantine equation is satisfiable under that parameter value. The use of natural numbers both in ''S'' and the existential quantification merely reflects the usual applications in computability and model theory. It does not matter whether natural numbers refer to the set of nonnegative integers or positive integers since the two definitions for Diophantine set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post–Turing Machine
A Post–Turing machineRajendra Kumar, ''Theory of Automata'', Tata McGraw-Hill Education, 2010, p. 343. is a "program formulation" of a type of Turing machine, comprising a variant of Emil Post's Turing-equivalent model of computation. Post's model and Turing's model, though very similar to one another, were developed independently. Turing's paper was received for publication in May 1936, followed by Post's in October. A Post–Turing machine uses a binary alphabet, an infinite sequence of binary storage locations, and a primitive programming language with instructions for bi-directional movement among the storage locations and alteration of their contents one at a time. The names "Post–Turing program" and "Post–Turing machine" were used by Martin Davis in 1973–1974 (Davis 1973, p. 69ff). Later in 1980, Davis used the name "Turing–Post program" (Davis, in Steen p. 241). 1936: Post model In his 1936 paper "Finite Combinatory Processes—Formulation 1", ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
