This article is about the programming language. For the narrative device, see. For other uses, see. Prolog, First appeared 1972.pl,.pro,.P Major,,,,, Prolog,,,,,,,,,,. ISO Prolog, Edinburgh Prolog Influenced by Influenced,,,,,,,,,, • at Wikibooks Prolog is a language associated with. Prolog has its roots in, a, and unlike many other, Prolog is intended primarily as a programming language: the program logic is expressed in terms of relations, represented as facts. A computation is initiated by running a query over these relations.

Techniques of Logic Programming through the Prolog language. Prolog is based on. Applications, especially in the field of Artificial Intelligence. Although it is a.

The language was first conceived by a group around in Marseille, France, in the early 1970s and the first Prolog system was developed in 1972 by Colmerauer with Philippe Roussel. Prolog was one of the first logic programming languages, and remains the most popular among such languages today, with several free and commercial implementations available. The language has been used for,,,, and, as well as its original intended field of use,. Modern Prolog environments support the creation of, as well as administrative and networked applications. Call cl program from rpgle. Prolog is well-suited for specific tasks that benefit from rule-based logical queries such as searching databases, systems, and filling templates. Main article: In Prolog, program logic is expressed in terms of relations, and a computation is initiated by running a query over these relations.

Relations and queries are constructed using Prolog's single data type, the term. Relations are defined by clauses. Given a query, the Prolog engine attempts to find a of the negated query. If the negated query can be refuted, i.e., an instantiation for all free variables is found that makes the union of clauses and the singleton set consisting of the negated query false, it follows that the original query, with the found instantiation applied, is a of the program. This makes Prolog (and other logic programming languages) particularly useful for database, symbolic mathematics, and language parsing applications. Because Prolog allows impure, checking the of certain special predicates may have some deliberate, such as printing a value to the screen.

Because of this, the programmer is permitted to use some amount of conventional when the logical paradigm is inconvenient. It has a purely logical subset, called 'pure Prolog', as well as a number of extralogical features. Data types [ ] Prolog's single is the term.

Terms are either, numbers, variables or compound terms. • An atom is a general-purpose name with no inherent meaning. Examples of atoms include x, red, 'Taco', and 'some atom'. • Numbers can be. ISO standard compatible Prolog systems can check the Prolog flag 'bounded'.

Most of the major Prolog systems support arbitrary length integer numbers. Keygen mac crack. • Variables are denoted by a string consisting of letters, numbers and underscore characters, and beginning with an upper-case letter or underscore. Variables closely resemble variables in logic in that they are placeholders for arbitrary terms.

• A compound term is composed of an atom called a 'functor' and a number of 'arguments', which are again terms. Compound terms are ordinarily written as a functor followed by a comma-separated list of argument terms, which is contained in parentheses. The number of arguments is called the term's. An atom can be regarded as a compound term with zero.

An examples of compound terms is person_friends(zelda,[tom,jim]). Special cases of compound terms: • A List is an ordered collection of terms. It is denoted by square brackets with the terms separated by commas or in the case of the empty list, []. For example, [1,2,3] or [red,green,blue]. • Strings: A sequence of characters surrounded by quotes is equivalent to either a list of (numeric) character codes, a list of characters (atoms of length 1), or an atom depending on the value of the Prolog flag double_quotes. For example, 'to be, or not to be'.