<grammar root="root" xml:lang="en-US" version="1.0" 
                       xmlns="http://www.w3.org/2001/06/grammar"> 
   <rule id="root" scope="public">
       <ruleref uri="#Tag"/>
       <tag> $.Tag = $$ </tag>
   </rule>
   <rule id="Tag" scope="public">
       <one-of>
           <item>prompt<tag> $._value = "prompt"</tag></item>
           <item>listen<tag> $._value = "listen"</tag></item>
           <item>grammar<tag> $._value = "grammar"</tag></item>
	   <item>bind<tag> $._value = "bind"</tag></item>
       </one-of>
   </rule>
</grammar>

Example 3: Grammar syntax.