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Let Expression
In computer science, a "let" expression associates a function definition with a restricted scope. The "let" expression may also be defined in mathematics, where it associates a Boolean condition with a restricted scope. The "let" expression may be considered as a lambda abstraction applied to a value. Within mathematics, a let expression may also be considered as a conjunction of expressions, within an existential quantifier which restricts the scope of the variable. The let expression is present in many functional languages to allow the local definition of expression, for use in defining another expression. The let-expression is present in some functional languages in two forms; let or "let rec". Let rec is an extension of the simple let expression which uses the fixed-point combinator to implement recursion. History Dana Scott's LCF language was a stage in the evolution of lambda calculus into modern functional languages. This language introduced the let expression, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Function (computer Science)
In computer programming, a function or subroutine is a sequence of program instructions that performs a specific task, packaged as a unit. This unit can then be used in programs wherever that particular task should be performed. Functions may be defined within programs, or separately in libraries that can be used by many programs. In different programming languages, a function may be called a routine, subprogram, subroutine, method, or procedure. Technically, these terms all have different definitions, and the nomenclature varies from language to language. The generic umbrella term ''callable unit'' is sometimes used. A function is often coded so that it can be started several times and from several places during one execution of the program, including from other functions, and then branch back (''return'') to the next instruction after the ''call'', once the function's task is done. The idea of a subroutine was initially conceived by John Mauchly during his work on ENIAC, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Computer Society
Sir Maurice Wilkes served as the first President of BCS in 1957 BCS, The Chartered Institute for IT, known as the British Computer Society until 2009, is a professional body and a learned society that represents those working in information technology (IT) and computer science, both in the United Kingdom and internationally. Founded in 1957, BCS has played an important role in educating and nurturing IT professionals, computer scientists, computer engineers, upholding the profession, accrediting chartered IT professional status, and creating a global community active in promoting and furthering the field and practice of computing. Overview With a worldwide membership of 57,625 members as of 2021, BCS is a registered charity and was incorporated by Royal Charter in 1984. Its objectives are to promote the study and application of communications technology and computing technology and to advance knowledge of education in ICT for the benefit of professional practitioners a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constraint Logic Programming
Constraint logic programming is a form of constraint programming, in which logic programming is extended to include concepts from constraint satisfaction. A constraint logic program is a logic program that contains constraints in the body of clauses. An example of a clause including a constraint is . In this clause, is a constraint; A(X,Y), B(X), and C(Y) are literals as in regular logic programming. This clause states one condition under which the statement A(X,Y) holds: X+Y is greater than zero and both B(X) and C(Y) are true. As in regular logic programming, programs are queried about the provability of a goal, which may contain constraints in addition to literals. A proof for a goal is composed of clauses whose bodies are satisfiable constraints and literals that can in turn be proved using other clauses. Execution is performed by an interpreter, which starts from the goal and recursively scans the clauses trying to prove the goal. Constraints encountered during this scan ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curry's Paradox
Curry's paradox is a paradox in which an arbitrary claim ''F'' is proved from the mere existence of a sentence ''C'' that says of itself "If ''C'', then ''F''", requiring only a few apparently innocuous logical deduction rules. Since ''F'' is arbitrary, any logic having these rules allows one to prove everything. The paradox may be expressed in natural language and in various logics, including certain forms of set theory, lambda calculus, and combinatory logic. The paradox is named after the logician Haskell Curry. It has also been called Löb's paradox after Martin Hugo Löb, due to its relationship to Löb's theorem. In natural language Claims of the form "if A, then B" are called conditional claims. Curry's paradox uses a particular kind of self-referential conditional sentence, as demonstrated in this example: Even though Germany does not border China, the example sentence certainly is a natural-language sentence, and so the truth of that sentence can be analyzed. The p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metaprogramming
Metaprogramming is a programming technique in which computer programs have the ability to treat other programs as their data. It means that a program can be designed to read, generate, analyze or transform other programs, and even modify itself while running. In some cases, this allows programmers to minimize the number of lines of code to express a solution, in turn reducing development time. It also allows programs a greater flexibility to efficiently handle new situations without recompilation. Metaprogramming can be used to move computations from run-time to compile-time, to generate code using compile time computations, and to enable self-modifying code. The ability of a programming language to be its own metalanguage is called reflection. Reflection is a valuable language feature to facilitate metaprogramming. Metaprogramming was popular in the 1970s and 1980s using list processing languages such as LISP. LISP hardware machines were popular in the 1980s and enabled app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narrowing Of Algebraic Value Sets
Like logic programming, narrowing of algebraic value sets gives a method of reasoning about the values in unsolved or partially solved equations. Where logic programming relies on resolution, the algebra of value sets relies on narrowing rules. Narrowing rules allow the elimination of values from a solution set which are inconsistent with the equations being solved. Unlike logic programming, narrowing of algebraic value sets makes no use of backtracking. Instead all values are contained in value sets, and are considered in parallel. The approach is also similar to the use of constraints in constraint logic programming, but without the logic processing basis. Probabilistic value sets is a natural extension of value sets to deductive probability. The value set construct holds the information required to calculate probabilities of calculated values based on probabilities of initial values. History Early programming languages were imperative. These implement functionalit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syntactic Sugar
In computer science, syntactic sugar is syntax within a programming language that is designed to make things easier to read or to express. It makes the language "sweeter" for human use: things can be expressed more clearly, more concisely, or in an alternative style that some may prefer. Syntactic sugar is usually a shorthand for a common operation that could also be expressed in an alternate, more verbose, form: The programmer has a choice of whether to use the shorter form or the longer form, but will usually use the shorter form since it is shorter and easier to type and read. For example, many programming languages provide special syntax for referencing and updating array elements. Abstractly, an array reference is a procedure of two arguments: an array and a subscript vector, which could be expressed as get_array(Array, vector(i,j)). Instead, many languages provide syntax such as Array ,j/code>. Similarly an array element update is a procedure consisting of three arguments, for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Let Definition In Mathematics
Let or LET may refer to: Sports * Let serve, when the served object in certain racket sports hits the net and lands in the correct service court, such as; ** Let (badminton) ** Let (pickleball) ** Let (tennis) * Ladies European Tour, the ladies professional golf tour of Europe Terminology * -let as an English diminutive suffix * Let expression, a name binding construct in computer programming languages * Let statement, a statement used in word problems requiring algebraic equations * Letting, a system of payment for the temporary use of something owned by someone else, also known as "rental" People, titles, characters * Licensed Engineering Technologist * Let, a fictional character from the anime series ''Rave Master'' Places, locations * County Leitrim, Ireland, Chapman code LET * Let, West Virginia * Leț, a village in Boroșneu Mare Commune, Covasna County, Romania * Alfredo Vásquez Cobo International Airport (IATA code LET), Leticia, Colombia * Lei Tung station (station ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
No Dropping To Boolean
No (and variant writings) may refer to one of these articles: English language * ''Yes'' and ''no'' (responses) * A determiner in noun phrases Alphanumeric symbols * No (kana), a letter/syllable in Japanese script * No symbol, displayed 🚫 * Numero sign, a typographic symbol for the word 'number', also represented as "No." or similar variants Geography * Norway (ISO 3166-1 country code NO) ** Norwegian language (ISO 639-1 code "no"), a North Germanic language that is also the official language of Norway ** .no, the internet ccTLD for Norway * Lake No, in South Sudan * No, Denmark, village in Denmark * Nō, Niigata, a former town in Japan * No Creek (other) * Acronym for the U.S. city of New Orleans, Louisiana or its professional sports teams ** New Orleans Saints of the National Football League ** New Orleans Pelicans of the National Basketball Association Arts and entertainment Film and television * ''Dr. No'' (film), a 1962 ''James Bond'' film ** Julius No ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
No Lifting From Boolean
No (and variant writings) may refer to one of these articles: English language * ''Yes'' and ''no'' (responses) * A determiner in noun phrases Alphanumeric symbols * No (kana), a letter/syllable in Japanese script * No symbol, displayed 🚫 * Numero sign, a typographic symbol for the word 'number', also represented as "No." or similar variants Geography * Norway (ISO 3166-1 country code NO) ** Norwegian language (ISO 639-1 code "no"), a North Germanic language that is also the official language of Norway ** .no, the internet ccTLD for Norway * Lake No, in South Sudan * No, Denmark, village in Denmark * Nō, Niigata, a former town in Japan * No Creek (other) * Acronym for the U.S. city of New Orleans, Louisiana or its professional sports teams ** New Orleans Saints of the National Football League ** New Orleans Pelicans of the National Basketball Association Arts and entertainment Film and television * ''Dr. No'' (film), a 1962 ''James Bond'' film ** Julius No ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambda Lifting
Lambda lifting is a meta-process that restructures a computer program so that functions are defined independently of each other in a global scope. An individual "lift" transforms a local function into a global function. It is a two step process, consisting of; * Eliminating free variables in the function by adding parameters. * Moving functions from a restricted scope to broader or global scope. The term "lambda lifting" was first introduced by Thomas Johnsson around 1982 and was historically considered as a mechanism for implementing functional programming languages. It is used in conjunction with other techniques in some modern compilers. Lambda lifting is not the same as closure conversion. It requires all call sites to be adjusted (adding extra arguments to calls) and does not introduce a closure for the lifted lambda expression. In contrast, closure conversion does not require call sites to be adjusted but does introduce a closure for the lambda expression mapping free va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics with the major subdisciplines of number theory, algebra, geometry, and analysis, respectively. There is no general consensus among mathematicians about a common definition for their academic discipline. Most mathematical activity involves the discovery of properties of abstract objects and the use of pure reason to prove them. These objects consist of either abstractions from nature orin modern mathematicsentities that are stipulated to have certain properties, called axioms. A ''proof'' consists of a succession of applications of deductive rules to already established results. These results include previously proved theorems, axioms, andin case of abstraction from naturesome basic properties that are considered true starting points of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
