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Concurrent Logic Programming
Concurrent logic programming is a variant of logic programming in which programs are sets of guarded Horn clauses of the form: : The conjunction is called the guard of the clause, and is the commitment operator. Declaratively, guarded Horn clauses are read as ordinary logical implications: : However, procedurally, when there are several clauses whose heads match a given goal, then all of the clauses are executed in parallel, checking whether their guards hold. If the guards of more than one clause hold, then a committed choice is made to one of the clauses, and execution proceeds with the subgoals {{mono, B1, …, Bn of the chosen clause. These subgoals can also be executed in parallel. Thus concurrent logic programming implements a form of "don't care nondeterminism", rather than "don't know nondeterminism". History The first concurrent logic programming language was the Relational Language of Clark and Gregory, which was an offshoot of IC-Prolog. Later versions of co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic Programming
Logic programming is a programming paradigm which is largely based on formal logic. Any program written in a logic programming language is a set of sentences in logical form, expressing facts and rules about some problem domain. Major logic programming language families include Prolog, answer set programming (ASP) and Datalog. In all of these languages, rules are written in the form of ''clauses'': :H :- B1, …, Bn. and are read declaratively as logical implications: :H if B1 and … and Bn. H is called the ''head'' of the rule and B1, ..., Bn is called the ''body''. Facts are rules that have no body, and are written in the simplified form: :H. In the simplest case in which H, B1, ..., Bn are all atomic formulae, these clauses are called definite clauses or Horn clauses. However, there are many extensions of this simple case, the most important one being the case in which conditions in the body of a clause can also be negations of atomic formulas. Logic programming languag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horn Clauses
In mathematical logic and logic programming, a Horn clause is a logical formula of a particular rule-like form which gives it useful properties for use in logic programming, formal specification, and model theory. Horn clauses are named for the logician Alfred Horn, who first pointed out their significance in 1951. Definition A Horn clause is a clause (a disjunction of literals) with at most one positive, i.e. unnegated, literal. Conversely, a disjunction of literals with at most one negated literal is called a dual-Horn clause. A Horn clause with exactly one positive literal is a definite clause or a strict Horn clause; a definite clause with no negative literals is a unit clause, and a unit clause without variables is a fact;. A Horn clause without a positive literal is a goal clause. Note that the empty clause, consisting of no literals (which is equivalent to ''false'') is a goal clause. These three kinds of Horn clauses are illustrated in the following propositional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guard (computing)
In computer programming, a guard is a boolean expression that must evaluate to true if the program execution is to continue in the branch in question. Regardless of which programming language is used, a guard clause, guard code, or guard statement, is a check of integrity preconditions used to avoid errors during execution. Uses A typical example is checking that a reference about to be processed is not null, which avoids null-pointer failures. Other uses include using a boolean field for idempotence (so subsequent calls are nops), as in the dispose pattern. public string Foo(string username) Flatter code with less nesting The guard provides an early exit from a subroutine, and is a commonly used deviation from structured programming, removing one level of nesting and resulting in flatter code: replacing if guard with if not guard: return; .... Using guard clauses can be a refactoring technique to improve code. In general, less nesting is good, as it simplifies the code an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Committed Choice
Committed may refer to: Media * ''Committed'', a 1992 album by the Jamaican reggae fusion band Third World * ''Committed'' (comic strip), an American comic strip written and drawn by Michael Fry * Committed (vocal group), an a cappella group of six male vocalists from Huntsville, Alabama * '' Committed: A Skeptic Makes Peace with Marriage'', a 2010 book written by Elizabeth Gilbert Film * ''Committed'', a 1984 film created by Sheila McLaughlin * ''Committed'' (1991 film), a 1991 film starring Jennifer O'Neill * ''Committed'' (2000 film), a 2000 film directed and written by Lisa Krueger * ''Committed'', a 2014 Cypriot film by Stelana Kliris * ''Committed: The Toronto International Film Festival'', a 2010 one-hour documentary by Morgan Spurlock Television * ''Committed'' (CSI episode), a 2005 episode of the TV series ''CSI: Crime Scene Investigation'' * ''Committed'', a 2011 television film starring Andrea Roth * ''Committed'' (American TV series), an American television sitc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrent Prolog
Concurrent means happening at the same time. Concurrency, concurrent, or concurrence may refer to: Law * Concurrence, in jurisprudence, the need to prove both ''actus reus'' and ''mens rea'' * Concurring opinion (also called a "concurrence"), a legal opinion which supports the conclusion, though not always the reasoning, of the majority. * Concurrent estate, a concept in property law * Concurrent resolution, a legislative measure passed by both chambers of the United States Congress * Concurrent sentences, in criminal law, periods of imprisonment that are served simultaneously Computing * Concurrency (computer science), the property of program, algorithm, or problem decomposition into order-independent or partially-ordered units * Concurrent computing, the overlapping execution of multiple interacting computational tasks * Concurrence (quantum computing), a measure used in quantum information theory * Concurrent Computer Corporation, an American computer systems manufacturer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fifth Generation Computer
The Fifth Generation Computer Systems (FGCS) was a 10-year initiative begun in 1982 by Japan's Ministry of International Trade and Industry (MITI) to create computers using massively parallel computing and logic programming. It aimed to create an "epoch-making computer" with supercomputer-like performance and to provide a platform for future developments in artificial intelligence. FGCS was ahead of its time and a commercial failure. FGCS contributed greatly to the field of concurrent logic programming. The term "fifth generation" was intended to convey the system as being advanced. In the history of computing hardware, computers using vacuum tubes were called the first generation; transistors and diodes, the second; integrated circuits, the third; and those using microprocessors, the fourth. Whereas previous computer generations had focused on increasing the number of logic elements in a single CPU, the fifth generation, it was widely believed at the time, would instead turn to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ministry Of International Trade And Industry
The was a ministry of the Government of Japan from 1949 to 2001. The MITI was one of the most powerful government agencies in Japan and, at the height of its influence, effectively ran much of Japanese industrial policy, funding research and directing investment. In the wake of a 2000 study by Japan’s Ministry of Finance, it was determined that MITI's "Japanese model was not the source of Japanese competitiveness but the cause of our failure.” In 2001, MITI was merged with other agencies during the Central Government Reform to form the newly created Ministry of Economy, Trade and Industry (METI). History MITI was created with the split of the Ministry of Commerce and Industry in May 1949 and given the mission for coordinating international trade policy with other groups, such as the Bank of Japan, the Economic planning Agency, and the various commerce-related cabinet ministries. At the time it was created, Japan was still recovering from the economic disaster of World ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ehud Shapiro
Ehud Shapiro ( he, אהוד שפירא; born 1955) is a multi-disciplinary scientist, artist, entrepreneur and Professor of Computer Science and Biology at the Weizmann Institute of Science. With international reputation, he made fundamental contributions to many scientific disciplines. Shapiro was also an Internet pioneer, a successful Internet entrepreneur, and a pioneer and proponent of E-democracy. Shapiro is the founder of thBa RockBand and conceived its original artistic program. He is a winner of two ERC ( European Research Council) Advanced Grants. Education and Professional background Born in Jerusalem in 1955, the guiding light for Shapiro's scientific endeavors was the philosophy of science of Karl Popper, with which he became acquainted through a high-school project supervised by Moshe Kroy from the Department of Philosophy, Tel Aviv University. In 1979 Shaprio completed his undergraduate studies in Tel Aviv University in Mathematics and Philosophy with distinction. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrent Constraint Logic Programming
Concurrent constraint logic programming is a version of constraint logic programming aimed primarily at programming concurrent processes rather than (or in addition to) solving constraint satisfaction problems. Goals in constraint logic programming are evaluated concurrently; a concurrent process is therefore programmed as the evaluation of a goal by the Interpreter (computing), interpreter. Syntactically, concurrent constraints logic programs are similar to non-concurrent programs, the only exception being that clauses include Guard (computing), guards, which are constraints that may block the applicability of the clause under some conditions. Semantically, concurrent constraint logic programming differs from its non-concurrent versions because a goal evaluation is intended to realize a concurrent process rather than finding a solution to a problem. Most notably, this difference affects how the interpreter behaves when more than one clause is applicable: non-concurrent constraint lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic Programming
Logic programming is a programming paradigm which is largely based on formal logic. Any program written in a logic programming language is a set of sentences in logical form, expressing facts and rules about some problem domain. Major logic programming language families include Prolog, answer set programming (ASP) and Datalog. In all of these languages, rules are written in the form of ''clauses'': :H :- B1, …, Bn. and are read declaratively as logical implications: :H if B1 and … and Bn. H is called the ''head'' of the rule and B1, ..., Bn is called the ''body''. Facts are rules that have no body, and are written in the simplified form: :H. In the simplest case in which H, B1, ..., Bn are all atomic formulae, these clauses are called definite clauses or Horn clauses. However, there are many extensions of this simple case, the most important one being the case in which conditions in the body of a clause can also be negations of atomic formulas. Logic programming languag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nondeterministic Programming
A nondeterministic programming language is a language which can specify, at certain points in the program (called "choice points"), various alternatives for program flow. Unlike an if-then statement, the method of choice between these alternatives is not directly specified by the programmer; the program must decide at run time between the alternatives, via some general method applied to all choice points. A programmer specifies a limited number of alternatives, but the program must later choose between them. ("Choose" is, in fact, a typical name for the nondeterministic operator.) A hierarchy of choice points may be formed, with higher-level choices leading to branches that contain lower-level choices within them. One method of choice is embodied in backtracking systems (such as Amb, or unification in Prolog), in which some alternatives may "fail," causing the program to backtrack and try other alternatives. If all alternatives fail at a particular choice point, then an entire b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Programming Paradigms
Programming paradigms are a way to classify programming languages based on their features. Languages can be classified into multiple paradigms. Some paradigms are concerned mainly with implications for the execution model of the language, such as allowing side effects, or whether the sequence of operations is defined by the execution model. Other paradigms are concerned mainly with the way that code is organized, such as grouping a code into units along with the state that is modified by the code. Yet others are concerned mainly with the style of syntax and grammar. Common programming paradigms include: * imperative in which the programmer instructs the machine how to change its state, ** procedural which groups instructions into procedures, ** object-oriented which groups instructions with the part of the state they operate on, * declarative in which the programmer merely declares properties of the desired result, but not how to compute it ** functional in which the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |