Simple Rule Markup Language (SRML)
Date:  2001-05-17
From:  Margaret Thorpe (ILOG, S.A.)  mthorpe@ilog.fr
Extract from:
Simple Rule Markup Language (SRML): A General XML Rule Representation for Forward-chaining Rules

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Here is an example of a rule expressed using this syntax [see XML DTD]:

Rule:           Discount
Description:    If 
    the total purchase amount of a shopping cart is > 100$
                Then
                    Set the discount for the shopping cart to 0.1%

Traditional
Syntax:         rule Discount {
                    when {
                        ?s:ShoppingCart(purchaseAmount > 100);
                    } then {
                        update ?s { discount = 0.1; }
                    }
}

Rule Markup:

<rule name="Discount">
  <conditionPart>
    <simpleCondition className="ShoppingCart" objectVariable="s">
       <binaryExp operator="gt">
          <field name="purchaseAmount"/>
          <constant type="float" value="100"/>
       </binaryExp>
    </simpleCondition>
  </conditionPart>
  <actionPart>
    <modify>
      <variable name="s"/>
      <assignment>
         <field name="discount"/>
          <constant type="float" value="0.1"/>
      </assignment>
    </modify>
  </actionPart>
</rule>

Here is an example of a slightly more complex rule marked up using this
syntax:

Rule:           CrossSelling
Description:    If 
    Purchase includes a Videotape in the Shopping Cart
    AND
    The Videotape has a Soundtrack CD
    AND
    The Soundtrack CD is not already in the Shopping Cart
                Then
                    Suggest the addition of the Soundtrack CD to the Shopping Cart

Traditional
Syntax:         rule CrossSelling {
                  when {
                    ?s: ShoppingCart();
                    ?cd: CD();
                    ?vt: VideoTape(soundtrackCD == ?cd);
                    Purchase(shoppingCart == ?s; item == ?vt);
                    not Purchase(shoppingCart == ?s; item == ?cd);
                  } then {
                    assert Suggestion {
              shoppingCart = ?s;
              item = ?cd;
                    }
                  }
}


Rule Markup:

<rule name="CrossSelling">
  <conditionPart>
    <simpleCondition className="ShoppingCart" objectVariable="s"/>
    <simpleCondition className="CD" objectVariable="cd"/>
    <simpleCondition className="VideoTape" objectVariable="vt">
       <binaryExp operator="eq">
          <field name="soundtrackCD"/>
          <variable name="cd"/>
       </binaryExp>
    </simpleCondition>
    <simpleCondition className="Purchase">
       <binaryExp operator="eq">
          <field name="shoppingCart"/>
          <variable name="s"/>
       </binaryExp>
       <binaryExp operator="eq">
          <field name="item"/>
          <variable name="vt"/>
       </binaryExp>
    </simpleCondition>
    <notCondition className="Purchase">
       <binaryExp operator="eq">
          <field name="shoppingCart"/>
          <variable name="s"/>
       </binaryExp>
       <binaryExp operator="eq">
          <field name="item"/>
          <variable name="cd"/>
       </binaryExp>
    </notCondition>
  </conditionPart>
  <actionPart>
    <assert className="Suggestion">
      <assignment>
         <field name="shoppingCart"/>
         <variable name="s"/>
      </assignment>
      <assignment>
         <field name="item"/>
         <variable name="cd"/>
      </assignment>
    </assert>
  </actionPart>
</rule>