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Corrado Böhm
Corrado Böhm (17 January 1923 – 23 October 2017) was an Italian computer scientist and Professor Emeritus at the Sapienza University of Rome, University of Rome "La Sapienza", known especially for his contributions to the theory of structured programming, constructive mathematics, combinatory logic, lambda calculus, and the semantics and implementation of functional programming languages. Work In his PhD dissertation (in Mathematics, at ETH Zurich, 1951; published in 1954), Böhm describes for the first time a full Böhm's language, meta-circular compiler, that is a translation mechanism of a programming language, written in that same language. His most influential contribution is the so-called structured program theorem, published in 1966 together with Giuseppe Jacopini. Together with Alessandro Berarducci, he demonstrated an isomorphism between the strictly-positive algebraic data types and the polymorphic lambda-terms, otherwise known as Böhm–Berarducci encoding. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milan
Milan ( , , ; ) is a city in northern Italy, regional capital of Lombardy, the largest city in Italy by urban area and the List of cities in Italy, second-most-populous city proper in Italy after Rome. The city proper has a population of nearly 1.4 million, while its Metropolitan City of Milan, metropolitan city has 3.2 million residents. Within Europe, Milan is the fourth-most-populous List of urban areas in the European Union, urban area of the EU with 6.17 million inhabitants. According to national sources, the population within the wider Milan metropolitan area (also known as Greater Milan) is estimated between 7.5 million and 8.2 million, making it by far the List of metropolitan areas of Italy, largest metropolitan area in Italy and List of metropolitan areas in Europe, one of the largest in the EU.* * * * Milan is the economic capital of Italy, one of the economic capitals of Europe and a global centre for business, fashion and finance. Milan is reco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Böhm's Language
Böhm's language refers to the language, machine and a translation method developed by Corrado Böhm during the latter part of 1950. Böhm used this work as part of his dissertation, submitted in 1951 (amended after submission), published in 1954. The compiler Böhm's work described the first complete meta-circular compiler. The code for the compiler was remarkably precise, and consisted of only 114 lines of code. Since the language accepted only two kinds of expressions: fully parenthesized or without parenthesis, but with operator precedence, therefore the code of the compiler split into two parts. 59 lines were used to handle formulas with parenthesis, 51 to handle operator precedence expressions and 4 to decide between those two cases. Böhm's parsing technique for expressions had only linear complexity. It generated instructions to a structure similar to a binary tree. The language Böhm's language consisted of only assignment operations. It had no special construct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Böhm Tree
In the study of denotational semantics of the lambda calculus, Böhm trees, Lévy-Longo trees, and Berarducci trees are (potentially infinite) tree-like mathematical objects that capture the "meaning" of a term up to some set of "meaningless" terms. Motivation A simple way to read the meaning of a computation is to consider it as a mechanical procedure consisting of a finite number of steps that, when completed, yields a result. In particular, considering the lambda calculus as a rewriting system, each beta reduction step is a rewrite step, and once there are no further beta reductions the term is in normal form. We could thus, naively following Church's suggestion, say the meaning of a term is its normal form, and that terms without a normal form are meaningless. For example the meanings of I = λx.x and I I are both I. This works for any strongly normalizing subset of the lambda calculus, such as a typed lambda calculus. This naive assignment of meaning is however inadequate f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Pioneers In Computer Science
This is a list of people who made transformative breakthroughs in the creation, development and imagining of what computers could do. Pioneers ~ Items marked with a tilde are circa dates. See also * Computer Pioneer Award * IEEE John von Neumann Medal * Grace Murray Hopper Award * History of computing ** History of computing hardware ** History of computing hardware (1960s–present) ** History of software * List of computer science awards * List of computer scientists * List of Internet pioneers * List of people considered father or mother of a field § Computing * '' The Man Who Invented the Computer'' (2010 book) * List of Russian IT developers * List of Women in Technology International Hall of Fame inductees * Timeline of computing * Turing Award * Women in computing Women in computing were among the first programmers in the early 20th century, and contributed substantially to the industry. As technology and practices altered, the role of women as programme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structured Program Theorem
The structured program theorem, also called the Böhm–Jacopini theorem, is a result in programming language theory. It states that a class of control-flow graphs (historically called flowcharts in this context) can compute any computable function if it combines subprograms in only three specific ways ( control structures). These are #Executing one subprogram, and then another subprogram (sequence) #Executing one of two subprograms according to the value of a boolean expression (selection) #Repeatedly executing a subprogram as long as a boolean expression is true (iteration) The structured chart subject to these constraints, particularly the loop constraint implying a single exit (as described later in this article), may however use additional variables in the form of bits (stored in an extra integer variable in the original proof) in order to keep track of information that the original program represents by the program location. The construction was based on Böhm's programmin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Computer Science (journal)
''Theoretical Computer Science'' (''TCS'') is a computer science journal published by Elsevier, started in 1975 and covering theoretical computer science. The journal publishes 52 issues a year. It is abstracted and indexed by Scopus and the Science Citation Index. According to the Journal Citation Reports, its 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... is 0.827. References Computer science journals Elsevier academic journals Academic journals established in 1975 {{comp-sci-theory-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Of The ACM
''Communications of the ACM'' (''CACM'') is the monthly journal of the Association for Computing Machinery (ACM). History It was established in 1958, with Saul Rosen as its first managing editor. It is sent to all ACM members. Articles are intended for readers with backgrounds in all areas of computer science and information systems. The focus is on the practical implications of advances in information technology and associated management issues; ACM also publishes a variety of more theoretical journals. The magazine straddles the boundary of a science magazine, trade magazine, and a scientific journal. While the content is subject to peer review, the articles published are often summaries of research that may also be published elsewhere. Material published must be accessible and relevant to a broad readership. From 1960 onward, ''CACM'' also published algorithms, expressed in ALGOL. The collection of algorithms later became known as the Collected Algorithms of the ACM. CA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turing-complete
In computability theory, a system of data-manipulation rules (such as a model of computation, a computer's instruction set, a programming language, or a cellular automaton) is said to be Turing-complete or computationally universal if it can be used to simulate any Turing machine (devised by English mathematician and computer scientist Alan Turing). This means that this system is able to recognize or decode other data-manipulation rule sets. Turing completeness is used as a way to express the power of such a data-manipulation rule set. Virtually all programming languages today are Turing-complete. A related concept is that of Turing equivalence two computers P and Q are called equivalent if P can simulate Q and Q can simulate P. The Church–Turing thesis conjectures that any function whose values can be computed by an algorithm can be computed by a Turing machine, and therefore that if any real-world computer can simulate a Turing machine, it is Turing equivalent to a Turing ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P′′
P′′ (P double prime) is a primitive computer programming language created by Corrado BöhmBöhm, C.: "On a family of Turing machines and the related programming language", ICC Bull. 3, 185-194, July 1964.Böhm, C. and Jacopini, G.: "Flow diagrams, Turing machines and languages with only two formation rules", CACM 9(5), 1966. (Note: This is the most-cited paper on the structured program theorem.) in 1964 to describe a family of Turing machines. Definition \mathcal^ (hereinafter written P′′) is formally defined as a set of words on the four-instruction alphabet \, as follows: Syntax # R and \lambda are words in P′′. # If q_1 and q_2 are words in P′′, then q_1 q_2 is a word in P′′. # If q is a word in P′′, then (q) is a word in P′′. # Only words derivable from the previous three rules are words in P′′. Semantics * \ is the tape-alphabet of a Turing machine with left-infinite tape, \Box being the ''blank'' symbol, equivalent to c_0. * All instruction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Association For Theoretical Computer Science
The European Association for Theoretical Computer Science (EATCS) is an international organization with a European focus, founded in 1972. Its aim is to facilitate the exchange of ideas and results among theoretical computer scientists as well as to stimulate cooperation between the theoretical and the practical community in computer science. The major activities of the EATCS are: * Organization of ICALP, the International Colloquium on Automata, Languages and Programming;Brauer, Ute; Brauer, WilfriedEuropean Association for Theoretical Computer Science / About the Association / Silver Jubilee of EATCS/ref> * Publication of the ''Bulletin of the EATCS''; * Publication of a series of monographs and texts on theoretical computer science; * Publication of the journal ''Theoretical Computer Science''; * Publication of the journal '' Fundamenta Informaticae''. EATCS Award Each year, the EATCS Award is awarded in recognition of a distinguished career in theoretical computer scienc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contextual Equivalence
Observational equivalence is the property of two or more underlying entities being indistinguishable on the basis of their observable implications. Thus, for example, two scientific theories are observationally equivalent if all of their empirically testable predictions are identical, in which case empirical evidence cannot be used to distinguish which is closer to being correct; indeed, it may be that they are actually two different perspectives on one underlying theory. In econometrics, two parameter values (or two ''structures,'' from among a class of statistical models) are considered observationally equivalent if they both result in the same probability distribution of observable data. This term often arises in relation to the identification problem. In macroeconomics, it happens when you have multiple structural models, with different interpretation, but indistinguishable empirically. "the mapping between structural parameters and the objective function may not display a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
