# Prolog

Learn Prolog Now! Best Prolog language books. Most of Prolog textbooks are dull and examples are artificial and repetitive. They usually give no ideas on how particular feature is implemented and provide no mental framework, as if the authors conspired to hide the real knowledge from you. One of the most interesting discussion of Prolog is in context of Lisp can be found in Artificial Intelligence Modern Approach Stuart J. Russell, Peter Norvig Another book wriiten by a person who knows Lisp well is Prolog Programming for Artificial Intelligence by Ivan Bratko (Author) Old News ;-) Artificial Intelligence Modern Approach Stuart J.

I'll be rather thorough in explaining how things work for the benefit of the Prolog and Haskell illiterates out there, so if you're familiar with both you might want to tl;dr, or just bask in the glory that is Prolog and Haskell combined. At first this might seem somewhat difficult. Prolog doesn't have functions or procedures, but predicates. These have no return value (except succeed/fail). Code: Select all Or do we? SWI-Prolog FAQ. Using Difference Lists. I posted my enthusiasm about difference lists for Haskell earlier this month, but then became sidetracked by combinators and reading lists, so, let's get back on track. Difference lists are a (very) useful data structure in Prolog, particularly when it comes to parsing with definite clause grammars (DCGs) and when it comes to list construction (again, using DCGs).

Why? Well, to answer that question, let's examine the structure of difference lists. The Prolog (or relational) representation of a difference list is of the form: What that relation describes is that X is the difference of the pair of lists of (first) [1,2,3] appended with the list Yminus (second) the list Y. Well, what is the value of the list Y? "Big deal! " "Good point!

" With all their flexibility and power, in certain situations, a zipper is not the correct choice for some list processing tasks; the difference list's simplicity shines in these situations. Okay, I've finished throwing it down for now. > import Data.DList. Story To Tell - List Zippers in Haskell and Prolog. Earlier today I thought I’d solidify my understanding of zippers, at least with lists. I’m pretty eluded by the concept for other data structures for right now but I’m liking the idea of it for lists (though not exactly seeing the whole point of it yet).

So I wrote up a quick implementation in Haskell included here: module Listzip where import List data Zipper a = Zipper [a] a [a] deriving (Show, Eq) at n l = Zipper prefix item postfix where (prefix,item,postfix) = doBreak n l [] doBreak 0 (x:xs) acc = (List.reverse acc, x, xs) doBreak n (x:xs) acc = doBreak (n-1) xs (x:acc) next (Zipper pre i (x:xs)) = Zipper (pre ++ [i]) x xs prev (Zipper pre i post) = Zipper (init pre) (last pre) (i:post) I realized it might be handy to have that be a functor so I can fmap it, so I added a couple more lines: instance Functor Zipper where fmap f (Zipper pre i post) = Zipper (fmap f pre) (f i) (fmap f post) toList (Zipper pre i post) = pre ++ [i] ++ post That’s cool, because now I can do things like this: ?

» Zipper lists in Prolog Logtalking. April 30, 2013 I’m currently looking into zipper data structures. Searching the web for zippering lists for prolog, the third hit is this old blog post by Daniel Lyons (hi Daniel!) : But I don’t liked the calls to reverse/2 and append/3 and their implied performance hits. So, I just rewrote the code to eliminate the calls (and start list index at 1; this is not C! :-) % zipper(+Position, +List, -Zip, -Element) % % where Zip = zip(Before, Element, After) % % index starts at 1 zipper(Position, List, Zip, Element) :- zipper(Position, List, [], Zip, Element). zipper(1, [Head|Tail], Acc, zip(Acc,Head,Tail), Head). zipper(N, [Head|Tail], Acc, zip(Before,Element,After), Element) :- N > 1, M is N - 1, zipper(M, Tail, [Head|Acc], zip(Before,Element,After), Element). next(zip(Before,Element,[Head|Tail]), zip([Element|Before],Head,Tail)). previous(X, Y) :- next(Y, X).

Some sample queries: ? Logic grammars and XML Schema. Keywords: XML Schema; validation; Prolog; logic programming; logic grammars This document describes some possible applications of logic grammars to schema processing as described in the XML Schema specification. The term logic grammar is used to denote grammars written in logic-programming systems; the best known logic grammars are probably definite-clause grammars (DCGs), which are a built-in part of most Prolog systems. This paper works with definite-clause translation grammars (DCTGs), which employ a similar formalism but which more closely resemble attribute grammars as described by [Knuth 1968] and later writers; it is a bit easier to handle complex specifications with DCTGs than with DCGs. Both DCGs and DCTGs can be regarded as syntactic sugar for straight Prolog; before execution, both notations are translated into Prolog clauses in the usual notation. 1 Introduction 1.1 Background The work described here may be regarded, in part, as a test of these propositions. 2.4 A simple schema.

MiniKanren.org. One of the most commonly asked questions about miniKanren is how miniKanren differs from Prolog. Here is the answer Will Byrd gave to this question on Stack Overflow. This is a tricky question to answer, largely because there are so many variants of both miniKanren and Prolog. miniKanren and Prolog are really families of languages, which makes it difficult to compare their features, or even how they are used in practice. Because of this, please take everything I'm about to say with caution: if I say that Prolog uses depth-first search, be aware that many Prolog implementations support other search strategies, and that alternate search strategies can also be encoded at the meta-interpreter level.

Still, miniKanren and Prolog have different design philosophies, and make different trade-offs. Prolog is one of the two classic languages for symbolic artificial intelligence programming (the other classic language being Lisp). MiniKanren.org. Using Difference Lists. » Zipper lists in Prolog Logtalking. Definite Clause Grammars (DCGs) Definite Clause Grammars (DCGs) are convenient ways to represent grammatical relationships for various parsing applications. They can be used for natural language work, for creating formal command and programming languages. For example, DCG is an excellent tool for parsing and creating tagged input and output streams, such as HTML or XML. The index and table of contents in this documentation are generated by a Prolog program that uses DCG to parse the HTML, looking for headings and index entries. See Adventure in Prolog or Programming in Prolog by Clocksin and Mellish for tutorial information on DCGs and the difference lists used to implement them.

Parsing with Difference Lists Parsing is analyzing an input stream. Difference lists are powerful tools for parsing applications, in which the input stream is represented by difference lists. Difference lists are pairs of lists used to represent the list of elements (tokens, words, character codes, ...) being parsed. ? For example: ? DCG Syntax ? ? ? ? ? Tutorial -- Using Definite Clause Grammars in SWI-Prolog. Home By Anne Ogborn Thanks to Markus Triska. Large sections of this tutorial are taken directly from his tutorial, which is used by permission here. Introduction1 Definite Clause Grammars2 Relating Trees To Lists3 Left Recursion4 Right-hand Context Notation5 Implicitly Passing States Around6 Parsing From Files7 Implementation8 Error Handling9 A Few Practical HintsConclusion Introduction Who This Course Is For Anyone who: knows swi-Prolog reasonably welland wants to effectively generate or parse lists. The second item goes far beyond the usual task of parsing text most programmers associate with DCG's.

But, we traditionally associate DCG's with parsing text. Is this you? Getting The Most From This Course To get the most from this course, you'll need to Have a working swi-Prolog install Understand basic Prolog be able to use SWI-Prolog's environmentRead the textTry each example program. Different people will have different backgrounds and learning styles. Other resources Another DCG tutorial ? ? Not ? ? ? XML.com. April 25, 2001 Introduction: SW is AI Many Semantic Web advocates have gone out of their way to disassociate their visions and projects from the Artificial Intelligence moniker.

No surprise, since the AI label has been the kiss of, if not death, at least scorn, since Lisp machines were frozen out of the marketplace during the great "AI winter" of the mid-1980s. Lisp still suffers from its association with the AI label, though it does well by being connected with the actual technologies. However, it is a curious phenomenon that the AI label tends to get dropped once the problem AI researchers were studying becomes tractable to some degree and yields practical systems. Voice recognition and text-to-speech, expert systems, machine vision, text summarizers, and theorem provers are just a few examples of classic AI tech that has become part of the standard bag of tricks.

That seems to describe the Semantic Web pretty well. A Gentle Prolog Primer Prolog is an excellent prototyping language. ? RDF Applications with Prolog. Published on XML.com this if you're having trouble printing code examples RDF Applications with PrologBy Bijan Parsia July 25, 2001 In the first article in this series, I explained some of the semantics of RDF via Prolog (and vice versa). In this article, I'll explore some of the nitty-gritty of working with RDF in Prolog using the SWI-Prolog system. Using RDF with SWI-Prolog SWI-Prolog is a fast, robust, and free open-source Prolog system with great support for XML and RDF. All in all, a wonderful system both for play and for serious work, and for play that becomes serious work! A good example application of SWI-Prolog's RDF support is the online RDF parser demo.

First Steps with SWI-Prolog's RDF Tools SWI-Prolog comes bundled with several modules for parsing RDF/XML and manipulating the result at various levels of detail and convenience. ? And hitting enter. ? ? Two points. ? And I can test to see if it's in fact in the knowledge base: ? SWI-Prolog -- format/2. Is an atom, list of character codes, or a Prolog string. provides the arguments required by the format specification. If only one argument is required and this single argument is not a list, the argument need not be put in a list.

Otherwise the arguments are put in a list. Special sequences start with the tilde (~), followed by an optional numeric argument, optionally followed by a colon modifier (:), 116The colon modifiers is a SWI-Prolog extension, proposed by Richard O'Keefe. followed by a character describing the action to be undertaken. A numeric argument is either a sequence of digits, representing a positive decimal number, a sequence `<>, representing the character code value of the character (only useful for ~t) or a asterisk (*), in which case the numeric argument is taken from the next argument of the argument list, which should be a positive integer. E.g., the following three examples all pass 46 (.) to ~t: ? - format('~w ~46t ~w~72|~n', ['Title', 'Page']). ? ? Example: LtU Classic Archives. Here's an online tutorial that has some stuff on DCG's and Building Parse Trees for an expression grammar, since the basic DCG will only tell you whether the list of strings satisfies the grammar.

DCG's are also the natural language parsing formalism with the longest unbroken history. The tradition starts with Schieber and Pereira's classic Prolog and Natural Language Analysis that culminates in a English question answering program in DCG: "Talk". (code available at CMU AI Repository) Covington's book builds on Pereira and Schieber and adds a simple system for unification of untyped feature structures. Alan Black, Robin Cooper, Ian Lewin (1993) Prolog and Natural Language Semantics: Notes for AI3/4 Computational Semantics, also builds on Pereira and Schieber adding semantics and Discourse Representation Theory (DRT) and also has an analysis of Pereira's Chat-80 question answering program.

The most recent addition to the tradition is a set of online books on computational semantics. Prolog Programming: a do-it-yourself course for beginners. This is a course that I will teach at the 16th European Summer School in Logic, Language and Information which is going to take place in Nancy, France in August 2004. It will be a hands-on programming course for students of linguistics who don't have any prior experience in programming. Its aim is to give linguists an impression of what it means to program and to show them how straightforward it is to do some interesting things (like writing parsers for small grammars). According to the courses's aim, its focus will be on material that leads the students to practical programming.

In the first three lectures I will cover the basics of Prolog (knowledge bases and queries, matching and proof search, lists). The last two lectures will be devoted to Definite Clause Grammars (DCGs). Programming is something which cannot be learned without actually doing it. The course will be based on "Learn Prolog Now! " My name is Kristina Striegnitz. Prolog - Count the number of leaves in a tree. Grammar - Prolog DCG illustration please.

Problem - writing XML with Prolog. Permalink Raw Message Report Post by Herick.snakegenerate(ARQ) :-tell(ARQ),write(brother(ana,Y),write('write(' '), nl,write(' '), nl,write(''), nl,flush,tell(user). Write: generate(ARQ) :-tell(ARQ),write('<NODEROOT>'), nl,( brother(ana, Y),write(' <PARENT>'), nl,write(' <PEOPLE>'), write('ana'), write('</PEOPLE>'), nl,write(' <BROTHER>'), write(Y), write('</BROTHER>'), nl,write(' </PARENT>'), nl,fail; true),write('</NODEROOT>'), nl,told. In general, this is NOT a good way to write XML, because it is hardto remember what needs quoting and how. Let's handle your example another way: :- [library(sgml)]. document(element('NODEROOT',[],Brothers)) :-findall(element('PARENT',[],[element('PEOPLE',[],[ana]),element('BROTHER',[],[Y])]),brother(ana, Y),Brothers). generate(ARQ) :-document(XML),open(ARQ, write, Stream),xml_write(Stream, XML, []),close(Stream).

Astonishingly, the (9.2) "Output is generally much easier achieved directly fromProlog. " Prolog 3/4: XML Parsing « Virtuous Programmer. Coursenotes. Getting Started. Prolog Tutorial -- 2.7. RDF Applications with Prolog. Prolog Development Tools - ProDT - Eclipse IDE for Prolog. The Prolog Development Tool - A Prolog IDE for Eclipse [SE-Wiki] Algorithms for Computational Linguistics. Programming in XPCE/Prolog: Section 11.4. Yet More XML: with Prolog. Help: I want the whole answer. Anniepoo/amziexpertsystemsinprolog. Prolog Programming. Prolog Programming. Prolog Programming. Natural Language Processing Techniques in Prolog. Natural Language Processing With Prolog in the IBM Watson System | Association for Logic Programming. Prolog dcg. Case-Based Reasoning Software. Tutorial -- Web Applications in SWI-Prolog.

Prolmanual. Multilang. A Java/XML guide for prolog programmers on Windows 9X. A Java/XML guide for prolog programmers on Windows 9X. Prolog Guide - Resources. SWI Prolog. Prolog - parse with DCG. Prolog. Section(2,'4.12',swi('/doc/Manual/DCG.html')) Tutorial -- Using Definite Clause Grammars in SWI-Prolog. Expert Systems in Prolog. Inc. Adventure in Prolog. Csee.umbc. Simple-prolog-examples.

Learn Prolog Now! Prolog Studio | InterProlog Consulting. XSB. Why did Prolog lose steam? | Mark J. Nelson. Csv.pl -- Process CSV (Comma-Separated Values) data.