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data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <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"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Experimental tool and programming language</div> <p><b>An Abstract Agent Programming Language</b> or <b>Artificial Autonomous Agents Programming Language</b> or <b>3APL</b> (pronounced triple-A-P-L) is an experimental <a href="/wiki/Tool" title="Tool">tool</a> and <a href="/wiki/Programming_language" title="Programming language">programming language</a> for the development, implementation and testing of multiple <a href="/wiki/Cognitive" class="mw-redirect" title="Cognitive">cognitive</a> <a href="/wiki/Software_agent" title="Software agent">agents</a> using the <a href="/wiki/BDI_software_agent" class="mw-redirect" title="BDI software agent">Belief-Desire-Intention</a> (BDI) approach. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Overview">Overview</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=3APL&action=edit&section=1" title="Edit section: Overview"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>3APL was developed and is maintained by a team at the <a href="/wiki/Computer_science" title="Computer science">computer science</a> department of <a href="/wiki/Utrecht_University" title="Utrecht University">Utrecht University</a> in the <a href="/wiki/Netherlands" title="Netherlands">Netherlands</a>. It facilitates specification of cognitive agent behavior using actions, beliefs, goals, plans, and rules. It has been subject to at least 15 <a href="/wiki/Scientific_paper" class="mw-redirect" title="Scientific paper">papers</a> and <a href="/wiki/Academic_conference" title="Academic conference">conferences</a>, and at least 4 <a href="/wiki/Thesis" title="Thesis">theses</a>. </p> <div class="mw-heading mw-heading2"><h2 id="Platform">Platform</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=3APL&action=edit&section=2" title="Edit section: Platform"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The 3APL <a href="/wiki/Computer_platform" class="mw-redirect" title="Computer platform">platform</a> has a visual interface for the monitoring and <a href="/wiki/Debug" class="mw-redirect" title="Debug">debugging</a> of agents being run therein, and a <a href="/wiki/Syntax" title="Syntax">syntax</a>-coloring <a href="/wiki/Text_editor" title="Text editor">editor</a> for <a href="/wiki/Source_code" title="Source code">source code</a> editing. It has been released as a <a href="/wiki/Java_(programming_language)" title="Java (programming language)">Java</a>-based <a href="/wiki/Software" title="Software">software</a>, which comes with some specification Java <a href="/wiki/Interface_(java)" class="mw-redirect" title="Interface (java)">interfaces</a> that can be used to develop Java-based <a href="/wiki/Plug-in_(computing)" title="Plug-in (computing)">plug-ins</a> and <a href="/wiki/Library_(computer_science)" class="mw-redirect" title="Library (computer science)">libraries</a>. These can be used to provide a visible representation of a virtual environment, for instance. A 3APL platform can also connect in <a href="/wiki/Client_(computing)" title="Client (computing)">client</a> or <a href="/wiki/Server_(computing)" title="Server (computing)">server</a> roles to other 3APL platforms across a <a href="/wiki/Computer_networking" class="mw-redirect" title="Computer networking">network</a>, to allow <a href="/wiki/Communication" title="Communication">communication</a> among 3APL agents on each platform. A lightweight version of 3APL for <a href="/wiki/Mobile_application" class="mw-redirect" title="Mobile application">mobile applications</a>, named <a href="/wiki/3APL-M" class="mw-redirect" title="3APL-M">3APL-M</a> "<a href="/w/index.php?title=Toymaker_(software)&action=edit&redlink=1" class="new" title="Toymaker (software) (page does not exist)">Toymaker</a>", has also been released. </p> <div class="mw-heading mw-heading2"><h2 id="Language">Language</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=3APL&action=edit&section=3" title="Edit section: Language"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>The 3APL language is relatively simple. The syntax has basic <a href="/wiki/Boolean_logic" class="mw-redirect" title="Boolean logic">boolean</a> <a href="/wiki/Logical_operator" class="mw-redirect" title="Logical operator">logical operators</a> <a href="/wiki/Logical_conjunction" title="Logical conjunction">AND</a>, <a href="/wiki/Logical_disjunction" title="Logical disjunction">OR</a> and <a href="/wiki/Logical_negation" class="mw-redirect" title="Logical negation">NOT</a>, with IF-THEN-ELSE <a href="/wiki/Conditional_(programming)" class="mw-redirect" title="Conditional (programming)">conditional statements</a>, and WHILE-DO <a href="/wiki/Control_flow" title="Control flow">control flow</a> loop structures. While temporary <a href="/wiki/Variable_(programming)" class="mw-redirect" title="Variable (programming)">variables</a> cannot be created except by calling plug-in methods or belief/goal conditions, <a href="/wiki/Iteration" title="Iteration">iterative</a> counter loops can be constructed using a combination of WHILE-DO loops, beliefs and capabilities. </p><p>A 3APL agent contains formal definitions of agent beliefs, capabilities, goals and plans. Specifically, there are six skeletal blocks that must be defined. </p> <pre>PROGRAM "agent" BELIEFBASE {} CAPABILITIES {} GOALBASE {} PLANBASE {} PG-RULES {} PR-RULES {} </pre> <p>The beliefs, defined using <a href="/wiki/Prolog" title="Prolog">Prolog</a> syntax, are used to remember information and to perform logical <a href="/wiki/Computation" title="Computation">computations</a>. Beliefs can be read by one another, edited by the capabilities, and read by conditional statements in the plans. The initial beliefs of an agent can be defined in its belief base. </p> <pre>BELIEFBASE { status(standby). at(0,0). location(r1,2,4). location(r5,6,1). dirty(r1). dirty(r5). } </pre> <p>Capabilities define the prerequisites and effects of actions in a <a href="/wiki/Stanford_Research_Institute_Problem_Solver" title="Stanford Research Institute Problem Solver">STRIPS</a>-like format, reading preexisting beliefs, removing some using the NOT operator, and adding new ones by stating them. </p> <pre>CAPABILITIES { {status(S1)} SetStatus(S2) {NOT status(S1), status(S2)}, {at(X1,Y1)} NowAt(X2,Y2) {NOT at(X1,Y1), at(X2,Y2)}, {dirty(R)} Clean(R) {NOT dirty(R)} } </pre> <p>Goals are also defined using Prolog syntax, and new goals can be adopted during runtime. Initial goals are defined in the goal base. </p> <pre>GOALBASE { cleanRoom(r1). cleanRoom(r5). } </pre> <p>Each goal ideally has associated goal planning rules, its PG rules, which serve as an abstract plans and are called from the goals as long as their guard conditions are met. </p> <pre>PG-RULES { cleanRoom(R) <- dirty(R) | { SetStatus(cleaning(R)); goTo(R); clean(R); SetStatus(standby); } } </pre> <p>The PG rules in turn can call plan revision rules, or PR rules, which serve as subroutines, and can be called upon to execute lower level and/or repetitive tasks as long as their guard conditions are met. Initial plans are defined in the plan base, executed at the beginning of the <a href="/wiki/Deliberation" title="Deliberation">deliberation</a> cycle. </p> <pre>PLANBASE { SetStatus(started); } PR-RULES { goTo(R) <- location(R,X,Y) AND NOT at(X,Y) | { NowAt(X,Y); } clean(R) <- location(R,X,Y) AND at(X,Y) | { Clean(R); } } </pre> <p>External methods may be called to access the environments modeled in the plug-ins. However, <a href="/wiki/Parameter" title="Parameter">parameters</a> cannot be directly passed to the methods, which means that the known environment must be correspondingly modeled in the agent's beliefs. The call returns a Prolog list, which can then be processed by the agent's own <a href="/wiki/Predicate_logic" class="mw-redirect" title="Predicate logic">predicate logic</a>. </p> <pre>Java("JanitorWorld", moveNorth(), M); </pre> <p>Agents can also communicate with one another using <i>Send</i> commands. When a piece of information X is sent with the performative P from agent A to agent B, the sending action is recorded in A's belief base as <i>sent(B,P,X)</i> and is registered in B's belief base as <i>received(A,P,X)</i>. </p> <pre>Send(Partner,inform,dirty(R)); </pre> <div class="mw-heading mw-heading2"><h2 id="Download">Download</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=3APL&action=edit&section=4" title="Edit section: Download"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>3APL is available for <a href="/wiki/Download" title="Download">download</a> at the University of Utrecht's 3APL website, packaged with sample lone and communicative agents, and a <a href="/wiki/Discrete_space" title="Discrete space">discrete</a> multi-agent foreground environment plug-in called <a href="/w/index.php?title=BlockWorld&action=edit&redlink=1" class="new" title="BlockWorld (page does not exist)">BlockWorld</a>. </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=3APL&action=edit&section=5" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Autonomous_agent" title="Autonomous agent">Autonomous agent</a></li> <li><a href="/wiki/Cognitive_architecture" title="Cognitive architecture">Cognitive architecture</a></li> <li><a href="/wiki/Agent_communication_language" class="mw-redirect" title="Agent communication language">Agent communication language</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=3APL&action=edit&section=6" title="Edit section: Further reading"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="http://www.cs.uu.nl/3apl/download/java/userguide.pdf">3APL User Guide for Java version</a></li> <li><a rel="nofollow" class="external text" href="http://www.cs.uu.nl/3apl/deliberationcycle.pdf">3APL deliberation cycle</a></li></ul> <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=3APL&action=edit&section=7" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="http://www.cs.uu.nl/3apl/">3APL Homepage</a></li></ul>    </div><noscript><img src="https://auth.wikimedia.org/loginwiki/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=3APL&oldid=1165501190">https://en.wikipedia.org/w/index.php?title=3APL&oldid=1165501190</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Category</a>: <ul><li><a href="/wiki/Category:Agent-based_programming_languages" title="Category:Agent-based programming languages">Agent-based programming languages</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_matches_Wikidata" title="Category:Short description matches Wikidata">Short description matches Wikidata</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 15 July 2023, at 15:42<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. 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