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</div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" 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<div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox vevent"><caption class="infobox-title summary">Logtalk</caption><tbody><tr><th scope="row" class="infobox-label"><a href="/wiki/Programming_paradigm" title="Programming paradigm">Paradigm</a></th><td class="infobox-data"><a href="/wiki/Logic_programming" title="Logic programming">Logic programming</a>, <a href="/wiki/Object-oriented_programming" title="Object-oriented programming">object-oriented programming</a>, <a href="/wiki/Prototype-based_programming" title="Prototype-based programming">prototype-based programming</a></td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/Software_design" title="Software design">Designed by</a></th><td class="infobox-data">Paulo Moura</td></tr><tr><th scope="row" class="infobox-label">First appeared</th><td class="infobox-data">1998<span class="noprint">; 26 years ago</span><span style="display:none"> (<span class="bday dtstart published updated">1998</span>)</span></td></tr><tr><td colspan="2" class="infobox-full-data"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1257001546"></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="/wiki/Software_release_life_cycle" title="Software release life cycle">Stable release</a></th><td class="infobox-data"><div style="margin:0px;">3.66.0 / 30 May 2023<span class="noprint">; 17 months ago</span><span style="display:none"> (<span class="bday dtstart published updated">2023-05-30</span>)</span></div></td></tr><tr style="display:none"><td colspan="2"> </td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/Operating_system" title="Operating system">OS</a></th><td class="infobox-data"><a href="/wiki/Cross-platform" class="mw-redirect" title="Cross-platform">Cross-platform</a></td></tr><tr><th scope="row" class="infobox-label"><a href="/wiki/Software_license" title="Software license">License</a></th><td class="infobox-data"><a href="/wiki/Artistic_License_2.0" class="mw-redirect" title="Artistic License 2.0">Artistic License 2.0</a> (2.x) / <a href="/wiki/Apache_License_2.0" class="mw-redirect" title="Apache License 2.0">Apache License 2.0</a> (3.01.x)</td></tr><tr><th scope="row" class="infobox-label">Website</th><td class="infobox-data"><span class="url"><a rel="nofollow" class="external text" href="https://logtalk.org">logtalk<wbr />.org</a></span></td></tr><tr><th colspan="2" class="infobox-header" style="background-color: #eee;">Influenced by</th></tr><tr><td colspan="2" class="infobox-full-data"><a href="/wiki/Prolog" title="Prolog">Prolog</a>, <a href="/wiki/Smalltalk" title="Smalltalk">Smalltalk</a>, <a href="/wiki/Objective-C" title="Objective-C">Objective-C</a></td></tr></tbody></table> <p><b>Logtalk</b> is an <a href="/wiki/Object-oriented_programming" title="Object-oriented programming">object-oriented</a> <a href="/wiki/Logic_programming" title="Logic programming">logic programming</a> language that extends and leverages the <a href="/wiki/Prolog" title="Prolog">Prolog</a> language with a feature set suitable for <a href="/wiki/Programming_in_the_large" class="mw-redirect" title="Programming in the large">programming in the large</a>.<sup id="cite_ref-moura_2003_1-0" class="reference"><a href="#cite_note-moura_2003-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> It provides support for <a href="/wiki/Information_hiding" title="Information hiding">encapsulation and data hiding</a>, <a href="/wiki/Separation_of_concerns" title="Separation of concerns">separation of concerns</a> and enhanced <a href="/wiki/Code_reuse" title="Code reuse">code reuse</a>.<sup id="cite_ref-moura_2003_1-1" class="reference"><a href="#cite_note-moura_2003-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> Logtalk uses standard Prolog syntax with the addition of a few operators and directives. </p><p>The Logtalk language implementation is distributed under an <a href="/wiki/Open_source_license" class="mw-redirect" title="Open source license">open source license</a> and can run using a Prolog implementation (compliant with official and de facto standards)<sup id="cite_ref-moura_2003_1-2" class="reference"><a href="#cite_note-moura_2003-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> as the <a href="/wiki/Front_and_back_ends" class="mw-redirect" title="Front and back ends">back-end</a> compiler. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Features">Features</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Logtalk&action=edit&section=1" title="Edit section: Features"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Logtalk aims to bring together the advantages of object-oriented programming and logic programming.<sup id="cite_ref-moura_2003_1-3" class="reference"><a href="#cite_note-moura_2003-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> Object-orientation emphasizes developing discrete, reusable units of software, while logic programming emphasizes representing the knowledge of each object in a declarative way. </p><p>As an object-oriented programming language, Logtalk's major features include support for both <a href="/wiki/Class_(computer_science)" class="mw-redirect" title="Class (computer science)">classes</a> (with optional <a href="/wiki/Metaclass" title="Metaclass">metaclasses</a>) and <a href="/wiki/Prototype-based_programming" title="Prototype-based programming">prototypes</a>, parametric objects,<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Protocol_(object-oriented_programming)" class="mw-redirect" title="Protocol (object-oriented programming)">protocols</a> (<a href="/wiki/Interface_(object-oriented_programming)" title="Interface (object-oriented programming)">interfaces</a>), categories (components, <a href="/wiki/Aspect-oriented_programming" title="Aspect-oriented programming">aspects</a>, <a href="/wiki/Software_hot_patch#Hot_patching" class="mw-redirect" title="Software hot patch">hot patching</a>), <a href="/wiki/Multiple_inheritance" title="Multiple inheritance">multiple inheritance</a>, public/protected/private inheritance, <a href="/wiki/Event-driven_programming" title="Event-driven programming">event-driven programming</a>, high-level multi-threading programming,<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Reflection_(computer_science)" class="mw-redirect" title="Reflection (computer science)">reflection</a>, and automatic generation of documentation. </p><p>For Prolog programmers, Logtalk provides wide portability, featuring predicate <a href="/wiki/Namespace" title="Namespace">namespaces</a> (supporting both static and dynamic objects), public/protected/private object predicates, <a href="/wiki/Coinduction" title="Coinduction">coinductive predicates</a>, separation between interface and implementation, simple and intuitive meta-predicate semantics, <a href="/wiki/Lambda_calculus" title="Lambda calculus">lambda expressions</a>, <a href="/wiki/Definite_clause_grammar" title="Definite clause grammar">definite clause grammars</a>, term-expansion mechanism, and conditional compilation. It also provides a module system based on de facto standard core module functionality (internally, modules are compiled as prototypes). </p> <div class="mw-heading mw-heading2"><h2 id="Examples">Examples</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Logtalk&action=edit&section=2" title="Edit section: Examples"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Logtalk's syntax is based on Prolog: </p> <div class="mw-highlight mw-highlight-lang-logtalk mw-content-ltr" dir="ltr"><pre><span></span><span class="o">?-</span> <span class="k">write</span>(<span class="s">'Hello world'</span>), <span class="k">nl</span>. <span class="nv">Hello</span> world <span class="k">true</span>. </pre></div> <p>Defining an object: </p> <div class="mw-highlight mw-highlight-lang-logtalk mw-content-ltr" dir="ltr"><pre><span></span><span class="p">:- </span><span class="k">object</span>(my_first_object). <span class="p">  :- </span><span class="k">initialization</span>((<span class="k">write</span>(<span class="s">'Hello world'</span>), <span class="k">nl</span>)). <span class="p">  :- </span><span class="k">public</span>(p1<span class="o">/</span><span class="m">0</span>). p1 <span class="o">:-</span> <span class="k">write</span>(<span class="s">'This is a public predicate'</span>), <span class="k">nl</span>. <span class="p">  :- </span><span class="k">private</span>(p2<span class="o">/</span><span class="m">0</span>). p2 <span class="o">:-</span> <span class="k">write</span>(<span class="s">'This is a private predicate'</span>), <span class="k">nl</span>. <span class="p">:- </span><span class="k">end_object</span>. </pre></div> <p>Using the object, assuming is saved in a my_first_object.lgt file: </p> <div class="mw-highlight mw-highlight-lang-logtalk mw-content-ltr" dir="ltr"><pre><span></span><span class="o">?-</span> <span class="k">logtalk_load</span>(my_first_object). <span class="nv">Hello</span> world <span class="k">true</span>. <span class="o">?-</span> my_first_object<span class="o">::</span>p1. <span class="nv">This</span> <span class="k">is</span> a public predicate <span class="k">true</span>. </pre></div> <p>Trying to access the private predicate gives an error: </p> <div class="mw-highlight mw-highlight-lang-logtalk mw-content-ltr" dir="ltr"><pre><span></span><span class="o">?-</span> my_first_object<span class="o">::</span>p2. <span class="nv">ERROR</span><span class="o">:</span> error(<span class="k">permission_error</span>(access, private_predicate, p2), my_first_object<span class="o">::</span>p2, user) </pre></div> <div class="mw-heading mw-heading3"><h3 id="Anonymous_functions">Anonymous functions</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Logtalk&action=edit&section=3" title="Edit section: Anonymous functions"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="excerpt-block"><style data-mw-deduplicate="TemplateStyles:r1066933788">.mw-parser-output .excerpt-hat .mw-editsection-like{font-style:normal}</style><style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable dablink excerpt-hat selfref">This section is an excerpt from <a href="/wiki/Examples_of_anonymous_functions#Logtalk" title="Examples of anonymous functions">Examples of anonymous functions § Logtalk</a>.<span class="mw-editsection-like plainlinks"><span class="mw-editsection-bracket">[</span><a class="external text" href="https://en.wikipedia.org/w/index.php?title=Examples_of_anonymous_functions&action=edit#Logtalk">edit</a><span class="mw-editsection-bracket">]</span></span></div><div class="excerpt"> <p>Logtalk uses the following syntax for anonymous predicates (lambda expressions): </p> <div class="mw-highlight mw-highlight-lang-logtalk mw-content-ltr" dir="ltr"><pre><span></span><span class="k">{</span><span class="nv">FreeVar1</span>, <span class="nv">FreeVar2</span>, ...<span class="k">}</span><span class="o">/</span>[<span class="nv">LambdaParameter1</span>, <span class="nv">LambdaParameter2</span>, ...]<span class="o">>></span><span class="nv">Goal</span> </pre></div> <p>A simple example with no free variables and using a list mapping predicate is: </p> <div class="mw-highlight mw-highlight-lang-logtalk mw-content-ltr" dir="ltr"><pre><span></span>| <span class="o">?-</span> meta<span class="o">::</span>map([<span class="nv">X</span>,<span class="nv">Y</span>]<span class="o">>></span>(<span class="nv">Y</span> <span class="k">is</span> <span class="m">2</span><span class="o">*</span><span class="nv">X</span>), [<span class="m">1</span>,<span class="m">2</span>,<span class="m">3</span>], <span class="nv">Ys</span>). <span class="nv">Ys</span> <span class="o">=</span> [<span class="m">2</span>,<span class="m">4</span>,<span class="m">6</span>] yes </pre></div> <p>Currying is also supported. The above example can be written as: </p> <div class="mw-highlight mw-highlight-lang-logtalk mw-content-ltr" dir="ltr"><pre><span></span>| <span class="o">?-</span> meta<span class="o">::</span>map([<span class="nv">X</span>]<span class="o">>></span>([<span class="nv">Y</span>]<span class="o">>></span>(<span class="nv">Y</span> <span class="k">is</span> <span class="m">2</span><span class="o">*</span><span class="nv">X</span>)), [<span class="m">1</span>,<span class="m">2</span>,<span class="m">3</span>], <span class="nv">Ys</span>). <span class="nv">Ys</span> <span class="o">=</span> [<span class="m">2</span>,<span class="m">4</span>,<span class="m">6</span>] yes </pre></div></div></div> <div class="mw-heading mw-heading2"><h2 id="Prolog_back-end_compatibility">Prolog back-end compatibility</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Logtalk&action=edit&section=4" title="Edit section: Prolog back-end compatibility"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Supported back-end Prolog compilers include <a href="/wiki/BProlog" class="mw-redirect" title="BProlog">B-Prolog</a>, <a href="/wiki/Ciao_(programming_language)" title="Ciao (programming language)">Ciao Prolog</a>, CxProlog, <a href="/wiki/ECLiPSe" title="ECLiPSe">ECLiPSe</a>, <a href="/wiki/GNU_Prolog" title="GNU Prolog">GNU Prolog</a>, JIProlog, <a href="/wiki/Quintus_Prolog" title="Quintus Prolog">Quintus Prolog</a>, Scryer Prolog, <a href="/wiki/SICStus_Prolog" title="SICStus Prolog">SICStus Prolog</a>, <a href="/wiki/SWI-Prolog" title="SWI-Prolog">SWI-Prolog</a>, Tau Prolog, Trealla Prolog, <a href="/wiki/XSB" title="XSB">XSB</a>, and <a href="/wiki/YAP_(Prolog)" title="YAP (Prolog)">YAP</a>.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> Logtalk allows use of back-end Prolog compiler libraries from within object and categories. </p> <div class="mw-heading mw-heading2"><h2 id="Developer_tools">Developer tools</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Logtalk&action=edit&section=5" title="Edit section: Developer tools"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Logtalk features on-line help, a documenting tool (that can generate PDF and HTML files), an entity diagram generator tool, a built-in debugger (based on an extended version of the traditional Procedure Box model found on most Prolog compilers), a unit test framework with code coverage analysis, and is also compatible with selected back-end Prolog profilers and graphical tracers.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Applications">Applications</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Logtalk&action=edit&section=6" title="Edit section: Applications"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Logtalk has been used to process <a href="/wiki/ISO_10303-21" title="ISO 10303-21">STEP</a> data models used to exchange <a href="/wiki/Product_manufacturing_information" class="mw-redirect" title="Product manufacturing information">product manufacturing information</a>.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> It has also been used to implement a reasoning system that allows preference reasoning and <a href="/wiki/Constraint_solving" class="mw-redirect" title="Constraint solving">constraint solving</a>.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Logtalk&action=edit&section=7" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Mercury_(programming_language)" title="Mercury (programming language)">Mercury (programming language)</a></li> <li><a href="/wiki/Oz_(programming_language)" title="Oz (programming language)">Oz (programming language)</a></li> <li><a href="/wiki/Prolog%2B%2B" title="Prolog++">Prolog++</a></li> <li><a href="/wiki/Visual_Prolog" title="Visual Prolog">Visual Prolog</a></li> <li><a href="/wiki/Comparison_of_Prolog_implementations" title="Comparison of Prolog implementations">Comparison of Prolog implementations</a></li> <li><a href="/wiki/Prolog_syntax_and_semantics" title="Prolog syntax and semantics">Prolog syntax and semantics</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Logtalk&action=edit&section=8" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-moura_2003-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-moura_2003_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-moura_2003_1-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-moura_2003_1-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-moura_2003_1-3"><sup><i><b>d</b></i></sup></a></span> <span class="reference-text">Paulo Moura (2003). Logtalk: Design of an Object-Oriented Logic Programming Language. PhD thesis. Universidade da Beira Interior</span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFMoura2011" class="citation conference cs1">Moura, Paulo (2011). <i>Programming Patterns for Logtalk Parametric Objects</i>. Applications of Declarative Programming and Knowledge Management. Lecture Notes in Computer Science. Vol. 6547. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2F978-3-642-20589-7_4">10.1007/978-3-642-20589-7_4</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-642-20588-0" title="Special:BookSources/978-3-642-20588-0"><bdi>978-3-642-20588-0</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=conference&rft.btitle=Programming+Patterns+for+Logtalk+Parametric+Objects&rft.series=Lecture+Notes+in+Computer+Science&rft.date=2011&rft_id=info%3Adoi%2F10.1007%2F978-3-642-20589-7_4&rft.isbn=978-3-642-20588-0&rft.aulast=Moura&rft.aufirst=Paulo&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALogtalk" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1"><i>Practical Aspects of Declarative Languages</i>. Lecture Notes in Computer Science. Vol. 4902. 2008. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2F978-3-540-77442-6">10.1007/978-3-540-77442-6</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-540-77441-9" title="Special:BookSources/978-3-540-77441-9"><bdi>978-3-540-77441-9</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Practical+Aspects+of+Declarative+Languages&rft.series=Lecture+Notes+in+Computer+Science&rft.date=2008&rft_id=info%3Adoi%2F10.1007%2F978-3-540-77442-6&rft.isbn=978-3-540-77441-9&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALogtalk" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://logtalk.org/compatibility.html">"Logtalk compatibility"</a>. Logtalk.org. 2016-10-10<span class="reference-accessdate">. Retrieved <span class="nowrap">2021-07-06</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Logtalk+compatibility&rft.pub=Logtalk.org&rft.date=2016-10-10&rft_id=http%3A%2F%2Flogtalk.org%2Fcompatibility.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALogtalk" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://github.com/LogtalkDotOrg/logtalk3/wiki/Developer-Tools">"Developer Tools – LogtalkDotOrg/logtalk3 Wiki – GitHub"</a>. Github.com. 2013-02-12<span class="reference-accessdate">. Retrieved <span class="nowrap">2013-08-19</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Developer+Tools+%E2%80%93+LogtalkDotOrg%2Flogtalk3+Wiki+%E2%80%93+GitHub&rft.pub=Github.com&rft.date=2013-02-12&rft_id=https%3A%2F%2Fgithub.com%2FLogtalkDotOrg%2Flogtalk3%2Fwiki%2FDeveloper-Tools&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALogtalk" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation book cs1"><i>Logic Programming</i>. Lecture Notes in Computer Science. Vol. 4079. 2006. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2F11799573">10.1007/11799573</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-3-540-36635-5" title="Special:BookSources/978-3-540-36635-5"><bdi>978-3-540-36635-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Logic+Programming&rft.series=Lecture+Notes+in+Computer+Science&rft.date=2006&rft_id=info%3Adoi%2F10.1007%2F11799573&rft.isbn=978-3-540-36635-5&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALogtalk" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFVictor_NoëlAntonis_Kakas2009" class="citation conference cs1">Victor Noël; Antonis Kakas (2009). <a rel="nofollow" class="external text" href="ftp://ftp.irit.fr/IRIT/SMAC/DOCUMENTS/PUBLIS/lpnmr-09_noel-kakas.pdf"><i>Gorgias-C: Extending Argumentation with Constraint Solving</i></a> <span class="cs1-format">(PDF)</span>. Logic Programming and Nonmonotonic Reasoning. <a href="/wiki/Lecture_Notes_in_Computer_Science" title="Lecture Notes in Computer Science">Lecture Notes in Computer Science</a>. Vol. 5753. pp. 535–541.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=conference&rft.btitle=Gorgias-C%3A+Extending+Argumentation+with+Constraint+Solving&rft.series=Lecture+Notes+in+Computer+Science&rft.pages=535-541&rft.date=2009&rft.au=Victor+No%C3%ABl&rft.au=Antonis+Kakas&rft_id=ftp%3A%2F%2Fftp.irit.fr%2FIRIT%2FSMAC%2FDOCUMENTS%2FPUBLIS%2Flpnmr-09_noel-kakas.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3ALogtalk" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Logtalk&action=edit&section=9" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><span class="official-website"><span class="url"><a rel="nofollow" class="external text" href="https://logtalk.org">Official website</a></span></span></li> <li><a rel="nofollow" class="external text" href="https://logtalk.org/blog.html">Logtalking blog</a></li> <li>From Plain Prolog to Logtalk Objects: Effective Code Encapsulation and Reuse (Invited Talk). Paulo Moura. Proceedings of the 25th International Conference on Logic Programming (ICLP), July 2009. LNCS 5649. Springer-Verlag Berlin Heidelberg". 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