CCXML <transition> element

The CCXML specification states that the "name" attribute of 
the <transition> element is:
"An ECMAScript left hand side expression evaluating to a previously defined variable."

However, the samples from the same specification don't follow this proposition.
For example, "Accept or Reject a Call" sample :

<?xml version="1.0" encoding="UTF-8"?>
<ccxml version="1.0" xmlns="http://www.w3.org/2002/09/ccxml">
  <eventprocessor>
  
    <transition event="connection.alerting" name="evt">
      <log expr="'The number called is' + evt.connection.remote + '.'"/>
      <if cond="evt.connection.remote == 'tel:+18315551234'">
        <log expr="'Go away! we do not want to answer the phone.'"/>
        <reject/>
      <else/>
        <log expr="'We like you! We are going to answer the call.'"/>
        <accept/>
      </if>
    </transition>
    <transition event="connection.connected">
      <log expr="'Call was answered,Time to disconnect it.'"/>
      <disconnect/>
    </transition>
    <transition event="connection.disconnected">
      <log expr="'Call has been disconnected. Ending CCXML Session.'"/>
      <exit/>
    </transition>
    
  </eventprocessor>
</ccxml>

In this script, "evt" is not a "previously defined variable". 
It seems that evt should become a property of the transition object, but 
this is not what the specification says.

So, it seems that either the samples are not correct or the specification 
for <transition> element is not correct.