About Following the style of which until recently was the design of my blog
sister, little more than a month is changed ProLog appearance IR, although for different reasons-the same as during this time have maintained "silence" this area of \u200b\u200bpublication, so far has not made an explicit reference to this circumstance. Basically the redesign work has been to remove the tables as system layout, and make the latter entirely to CSS . The advantage of having the page structured in this way, regardless of maso least meet the standards existing the fact is that they are completely separate blocks of content from presentation itself, and thus more easily introduce future changes in style and appearance. In fact the style that you can see at this time intend to be provisional, since among other issues, and in its present configuration, may have some display problems in Internet Explorer (not!), Follow n is the screen resolution used.
Also I have in mind a future change hosting and publishing system (" WordPress ?) In the short term, if time and the desire to allow ... In any case, the important thing, and what it is, issues of style aside, is to offer interesting content, and in this sense I hope, "put the batteries" hereinafter, and that I've expanded over intervals publication, combines Although statistics show me that, rather than regular and loyal users, the profile of visitors to this site corresponds to accessing people, a significantly majority to through search engines (Google in particular, how could it be otherwise, at least today) and metasearch, and search the corresponding equations-some very interesting and surprising, indeed, whose analysis allows the time to establish if there is an appropriate match between the topics commonly addressed and searches equivalent to those issues by users. Well, now time to clarify the meaning and significance of the event which currently shares the spotlight with the top of the page: "Algorithm = Logic + Control." This "equation" very general, has made a fortune when explicit, graphic and condensed form, the principles and rationale implicit in the logic programming paradigm (associated with this scheme, so particular, logic programming with constraints), and in general in the analysis software, and it is not the title of an article in which author Robert Kowalski explains his notion of declarative programming in general and logical in particular, early development for the years when it was published. The full review of this paper is as follows: Kowalski, R. (1979), "Algorithm = logic + control, Communications of the ACM, 22 (7), pp. 424-436. [complete reference ] The full text PDF format is available in digital library of ACM , although access is limited to paying subscribers . It is freely accessible the record, the summary and the bibliography accompanying the text. The article was later republished in the work Programming Languages: A Grand Tour (3 rd edition, E. Horwitz ed., Computer Science Press: Maryland, 1986, pp. 480-492).
) and how the program should address this objective (the
how , the control). In this sense, the paradigm of logic programming, and in general the paradigm of declarative programming (which includes on one hand, functional programming - Haskell, Lisp , etc .- and other logic programming), clearly focuses on facilitating
what we want to do the program-its target of pre-, which
how you must do to achieve it, which does not exclude the existence of powerful control structures such as those which are represented in Prolog, by the mechanisms of instantiation of variables, and check
unification of structures, recursion
and backtracking
or reverse, to name the most important.
Chapter "Pandora's Box A = L + C and its variants", page 84 and following the notes of BC Ruiz Jiménez, Course Notes for Advanced
Declarative Programming (University of Málaga
, PDF format document
) provides a good EXPLANATION n the meaning and implications of the formula Kowalski. Indeed, in this paper can find a very clear articulation of synergy and symbiosis between certain projects provide programming paradigm represented in part by the language Prolog, and a number of approaches (functional, oriented objects etc.), as we mentioned in the previous annotation (" =" Logic Programming Prolog? ") concerning a notice published in Lambda the Ultimate . See paragraphs about "Logic Programming" and "Integrating logic and functional paradigms." Returning to the explanation of the equation Kowalski, interrupted by the reference in paragraph above, we can say that in Prolog, and given the characteristics of this programming language, the user is primarily concerned to implement the "logic" of programs (consisting mainly of the knowledge base, inference rules, and queries), as control mechanisms cited ; we were before, those who determine how solve specific objective program, implemented through a series of algorithms and mechanisms that work in-house, whose characteristics depend on the interpreter used last ( remember that Prolog is an interpreted language, if While some implementations allow certain instructions to pre-compile). arises at this point, associating with
control logic , the idea of \u200b\u200bconstraint programming and Constraint Programming to provide more controlled evaluation of control mechanisms, the scheme logic programming and thus to fully satisfying the maximum Kowalski, thus giving rise to the Constraint Logic Programming and Constraint Logic Programming (CLP). Some documents on constraint programming in general: Constraint Programming (M. Wallace, also in PS format, see especially section 2.1.1 . Algorithm = Logic + Control ). Constraint Programming (lecture notes of Professor Jia-Huai You ).
On-line guide to Constraint Programming
(R. Bartak, also the author of Guide to Prolog Programming ). on Constraint Logic Programming in particular see for example the following texts: An Introductory Course on Constraint Logic Programming (M. Carro et al. ).
Constraint Logic Programming - An Informal Introduction
(T. Frühwirth et al. ; format
PS). Constraint Logic Programming: A Survey (J. Jaffar, MJ Mayer, PS format).
Constraint Logic Programming
La
Programmation Logique et par Contraintes
(L. Jean-Michel en - Lambda
Systems ).
Algunas opiniones e interpretaciones al respecto de la "fórmula"
que venimos comentando:
-
"The basic property of a declarative programming language is
that a program is a theory in some suitable logic. This property immediately
gives a precise meaning to programs written in the language. From a programmers
point of the basic property is that programming is lifted to a higher level
of abstraction. At this higher level of abstraction the programmer can
concentrate stating on What Is To Be computed , Not Necessarily how it is to Be computed. In Kowalski's Terms WHERE algorithm = logic + control, the programmer Gives the logic But Not Necessarily the control. " Olof Torgersson in - A Note on Declarative Programming Paradigms and the Future of Definitional Programming (text in HTML
is a shortened version of the original PS - format)
- "The formula isn't required, and it Will not Be Until someone Proposes specifying a precise and Generally Accepted notion of how control is to Be added to an expression of the logic of a program. Nevertheless, the idea is attractive, and I believe it Can Be Made to work for Some interesting class of programs. It is analogous to my comparison of epistemology and heuristics or Chomsky's competence and performance. " John McCarthy in Coloring Maps and the Kowalski Doctrine
- In any case it offers a fairly detailed explanation of the expression n "Algorithm = Logic + Control" and its meaning in relation to logic programming, in another text of the Kowalski, Logic Problem Solving for (North-Holland Elsevier, 1979), specifically in Chapter 5,
- The Procedural Interpretation of Horn Clauses (PDF format , page 125 and following, although in fact the chapter ; whole chapter deals with this issue.) The chapters in this book, very affordable level, and full text are available in PDF in
personal page R. - Kowalski, which is also a selection of his latest literature and the preliminary draft chapters of the new book he is preparing How to be Artificially Intelligent - the Logical Way , which addresses the fundamental principles of computer logic, and implementation problems of everyday life. Kowalski will end by emphasizing that, along with Alain
Colmerauer
, one of the key figures in the development creacióny logic programming in general and Prolog in particular. Colmerauer, which since the late 60's of last century had been working on the processing and natural language processing through the application of computational logic, makes contact with Kowalski in 1971 to hear their work in relation to the Show No automatic theorem (theorem proving
) and the resolution method
SL (SL-resolution ), and fruit of this collaboration produced the first effective development of programming language No logic Prolog. Throughout this process, along with other notes autobiographical, is explained briefly in the same Kowalski in the text A Short Story of My Life and Work
.
