s=identifier><code>r </code></span><code><span class=special>= </span><span class=identifier>a </span><span class=special>| </span><span class=identifier>b</span><span class=special>;</span></code></pre>
<p>Spirit v1.3 allowed this behavior. However, the current version of Spirit <b>no 
  longer</b> allows this because experience shows that this behavior leads to 
  unwanted gotchas (for instance, it does not allow rules to be held in containers). 
  In the current release of Spirit, a second assignment to 