Example

The cond function allows three arguments. The first argument is called the condition. If the value of the condition is logically true, the value of the cond will be the value of the second argument. If the value of the condition is false, the value of the cond will be the value of the third argument. If the value of the condition is false, and the third argument not present, the value of the cond is null.

<cond>
     <gt>
      <ref>age</ref>
       <i>40</i>
     </gt>
   <s>old</s>
   <s>young</s>
</cond>