culations used in multiple places within an MXML document.
	 By binding the results of a complex boolean expression to a
	 BooleanExpression's value property, you allow other objects to bind
	 on that value without the overhead of re-running the original
	 expression.
	 
	 <p>
	 For example, this markup will populate two labels with the text
	 "true" but <code>(a || b || c || d || e || true)</code> will only have been
	 evaluated once.
	 </p>
	 
	              <pre>
	                 <code>
	 &lt;BooleanExp