likes.ruleml

<?xml version="1.0" encoding="UTF-8"?>

<RuleML
xmlns="http://www.ruleml.org/0.91/xsd"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.ruleml.org/0.91/xsd http://www.ruleml.org/0.91/xsd/datalog.xsd">

<!-- Clocksin/Mellish sample rule -->

  <Assert mapClosure="universal">

  <Implies>
    <head>
      <Atom>
        <op><Rel>likes</Rel></op>
        <Ind>John</Ind>
        <Var>x</Var>
      </Atom>
    </head>
    <body>
      <Atom>
        <op><Rel>likes</Rel></op>
        <Var>x</Var>
        <Ind>wine</Ind>
      </Atom>
    </body>
  </Implies>

  <Atom>
    <op><Rel>likes</Rel></op>
    <Ind>Mary</Ind>
    <Ind>wine</Ind>
  </Atom>
 
 </Assert>
 
 <Query>
   <Atom>
     <Rel>likes</Rel>
     <Ind>John</Ind>
     <Ind>whom</Ind>
   </Atom>
 </Query>
 
 <Retract>
   <Atom>
     <Rel>likes</Rel>
     <Ind>Mary</Ind>
     <Ind>wine</Ind>
   </Atom>
 </Retract>
 
</RuleML>