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Grigori Tseitin
Grigori Samuilovitsch Tseitin (, born November 15, 1936 in Leningrad, USSR, deceased August 27, 2022 in Campbell, CA, USA) was a Russian mathematician and computer scientist, who moved to the United States in 1999. He is best known for Tseitin transformation used in SAT solvers, Tseitin tautologies used in the proof complexity theory, and for his work on Algol 68. Biography Tseitin studied mathematics at the Leningrad State University (now Saint Petersburg State University) from 1951 to 1956. He earned his PhD in 1960 under the supervision of Andrei Andreevich Markov. His dissertation was called "Algorithmic Operators on Constructive Complete Separable Metric Spaces". In 1968, he received the Russian doctoral degree (corresponding to a habilitation Habilitation is the highest university degree, or the procedure by which it is achieved, in Germany, France, Italy, Poland and some other European and non-English-speaking countries. The candidate fulfills a university's set cri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematics
Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many areas of mathematics, which include number theory (the study of numbers), algebra (the study of formulas and related structures), geometry (the study of shapes and spaces that contain them), Mathematical analysis, analysis (the study of continuous changes), and set theory (presently used as a foundation for all mathematics). Mathematics involves the description and manipulation of mathematical object, abstract objects that consist of either abstraction (mathematics), abstractions from nature orin modern mathematicspurely abstract entities that are stipulated to have certain properties, called axioms. Mathematics uses pure reason to proof (mathematics), prove properties of objects, a ''proof'' consisting of a succession of applications of in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Science
Computer science is the study of computation, information, and automation. Computer science spans Theoretical computer science, theoretical disciplines (such as algorithms, theory of computation, and information theory) to Applied science, applied disciplines (including the design and implementation of Computer architecture, hardware and Software engineering, software). Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of computational problem, problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and preventing security vulnerabilities. Computer graphics (computer science), Computer graphics and computational geometry address the generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tseitin Transformation
The Tseytin transformation, alternatively written Tseitin transformation, takes as input an arbitrary combinatorial logic circuit and produces an equisatisfiable boolean formula in conjunctive normal form (CNF). The length of the formula is linear in the size of the circuit. Input vectors that make the circuit output "true" are in 1-to-1 correspondence with assignments that satisfy the formula. This reduces the problem of circuit satisfiability on any circuit (including any formula) to the satisfiability problem on 3-CNF formulas. It was discovered by the Russian scientist Grigori Tseitin. Motivation The naive approach is to write the circuit as a Boolean expression, and use De Morgan's law and the distributive property to convert it to CNF. However, this can result in an exponential increase in equation size. The Tseytin transformation outputs a formula whose size grows linearly relative to the input circuit's. Approach The output equation is the constant 1 set equal to an expr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1936
Events January–February * January 20 – The Prince of Wales succeeds to the throne of the United Kingdom as King Edward VIII, following the death of his father, George V, at Sandringham House. * January 28 – Death and state funeral of George V, State funeral of George V of the United Kingdom. After a procession through London, he is buried at St George's Chapel, Windsor Castle. * February 4 – Radium E (bismuth-210) becomes the first radioactive element to be made synthetically. * February 6 – The 1936 Winter Olympics, IV Olympic Winter Games open in Garmisch-Partenkirchen, Germany. * February 10–February 19, 19 – Second Italo-Ethiopian War: Battle of Amba Aradam – Italian forces gain a decisive tactical victory, effectively neutralizing the army of the Ethiopian Empire. * February 16 – 1936 Spanish general election: The left-wing Popular Front (Spain), Popular Front coalition takes a majority. * February 26 – February 26 Incident (二・二六事件, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tseytin Transformation
The Tseytin transformation, alternatively written Tseitin transformation, takes as input an arbitrary combinatorial logic circuit and produces an equisatisfiable boolean formula in conjunctive normal form (CNF). The length of the formula is linear in the size of the circuit. Input vectors that make the circuit output "true" are in 1-to-1 correspondence with assignments that satisfy the formula. This reduces the problem of circuit satisfiability on any circuit (including any formula) to the satisfiability problem on 3-CNF formulas. It was discovered by the Russian scientist Grigori Tseitin. Motivation The naive approach is to write the circuit as a Boolean expression, and use De Morgan's law and the distributive property to convert it to CNF. However, this can result in an exponential increase in equation size. The Tseytin transformation outputs a formula whose size grows linearly relative to the input circuit's. Approach The output equation is the constant 1 set equal to an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAT Solver
In computer science and formal methods, a SAT solver is a computer program which aims to solve the Boolean satisfiability problem (SAT). On input a formula over Boolean data type, Boolean variables, such as "(''x'' or ''y'') and (''x'' or not ''y'')", a SAT solver outputs whether the formula is satisfiability, satisfiable, meaning that there are possible values of ''x'' and ''y'' which make the formula true, or unsatisfiable, meaning that there are no such values of ''x'' and ''y''. In this case, the formula is satisfiable when ''x'' is true, so the solver should return "satisfiable". Since the introduction of algorithms for SAT in the 1960s, modern SAT solvers have grown into complex software, software artifacts involving a large number of heuristics and program optimizations to work efficiently. By a result known as the Cook–Levin theorem, Boolean satisfiability is an NP-completeness, NP-complete problem in general. As a result, only algorithms with exponential worst-case comple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algol 68
ALGOL 68 (short for ''Algorithmic Language 1968'') is an imperative programming language member of the ALGOL family that was conceived as a successor to the ALGOL 60 language, designed with the goal of a much wider scope of application and more rigorously defined syntax and semantics. The complexity of the language's definition, which runs to several hundred pages filled with non-standard terminology, made compiler implementation difficult and it was said it had "no implementations and no users". This was only partly true; ALGOL 68 did find use in several niche markets, notably in the United Kingdom where it was popular on International Computers Limited (ICL) machines, and in teaching roles. Outside these fields, use was relatively limited. Nevertheless, the contributions of ALGOL 68 to the field of computer science have been deep, wide-ranging and enduring, although many of these contributions were only publicly identified when they had reappeared in subsequently develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint Petersburg State University
Saint Petersburg State University (SPBGU; ) is a public research university in Saint Petersburg, Russia, and one of the oldest and most prestigious universities in Russia. Founded in 1724 by a decree of Peter the Great, the university from the beginning has had a focus on fundamental research in science, engineering and humanities. During the Soviet period, it was known as Leningrad State University (). It was renamed after Andrei Zhdanov in 1948 and was officially called "Leningrad State University, named after A. A. Zhdanov and decorated with the Order of Lenin and the Order of the Red Banner of Labour." Zhdanov's was removed in 1989 and Leningrad in the name was officially replaced with Saint Petersburg in 1992. It is made up of 24 specialized faculties (departments) and institutes, the Academic Gymnasium, the Medical College, the College of Physical Culture and Sports, Economics and Technology. The university has two primary campuses: one on Vasilievsky Island and the ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habilitation
Habilitation is the highest university degree, or the procedure by which it is achieved, in Germany, France, Italy, Poland and some other European and non-English-speaking countries. The candidate fulfills a university's set criteria of excellence in research, teaching, and further education, which usually includes a dissertation. The degree, sometimes abbreviated ''Dr. habil''. (), ''dr hab.'' (), or ''D.Sc.'' ('' Doctor of Sciences'' in Russia and some CIS countries), is often a qualification for full professorship in those countries. In German-speaking countries it allows the degree holder to bear the title ''PD'' (for ). In a number of countries there exists an academic post of docent, appointment to which often requires such a qualification. The degree conferral is usually accompanied by a public oral defence event (a lecture or a colloquium) with one or more opponents. Habilitation is usually awarded 5–15 years after a PhD degree or its equivalent. Achieving this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Association For Computing Machinery
The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 and is the world's largest scientific and educational computing society. The ACM is a non-profit professional membership group, reporting nearly 110,000 student and professional members . Its headquarters are in New York City. The ACM is an umbrella organization for academic and scholarly interests in computer science (informatics). Its motto is "Advancing Computing as a Science & Profession". History In 1947, a notice was sent to various people: On January 10, 1947, at the Symposium on Large-Scale Digital Calculating Machinery at the Harvard computation Laboratory, Professor Samuel H. Caldwell of Massachusetts Institute of Technology spoke of the need for an association of those interested in computing machinery, and of the need for communication between them. ..After making some inquiries during May and June, we believe there is ample interest to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1936 Births
Events January–February * January 20 – The Prince of Wales succeeds to the throne of the United Kingdom as King Edward VIII, following the death of his father, George V, at Sandringham House. * January 28 – Death and state funeral of George V, State funeral of George V of the United Kingdom. After a procession through London, he is buried at St George's Chapel, Windsor Castle. * February 4 – Radium E (bismuth-210) becomes the first radioactive element to be made synthetically. * February 6 – The 1936 Winter Olympics, IV Olympic Winter Games open in Garmisch-Partenkirchen, Germany. * February 10–February 19, 19 – Second Italo-Ethiopian War: Battle of Amba Aradam – Italian forces gain a decisive tactical victory, effectively neutralizing the army of the Ethiopian Empire. * February 16 – 1936 Spanish general election: The left-wing Popular Front (Spain), Popular Front coalition takes a majority. * February 26 – February 26 Incident (二・二六事件, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2022 Deaths
This is a list of lists of deaths of notable people, organized by year. New deaths articles are added to their respective month (e.g., Deaths in ) and then linked below. 2025 2024 2023 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 Earlier years ''Deaths in years earlier than this can usually be found in the main articles of the years.'' See also * Lists of deaths by day * Deaths by year (category) {{DEFAULTSORT:deaths by year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
