Flex: using logical conjunction in an MXML attribute

If you try to use the logical AND operator inside of an MXML attribute to determine its value, the compiler will throw this error:

The entity name must immediately follow the ‘&’ in the entity reference

The error message is sketchy, especially given the fact that the logical OR operator is allowed.
The ampersand needs to be html-encoded (after all, MXML is an XML-based markup language!)

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
	<mx:Script>
		<![CDATA[
		[Bindable] private var arg1:Boolean;
		[Bindable] private var arg2:Boolean;

		private function validate():Boolean {
			return (this.arg1 && this.arg2);
		}
		]]>
	</mx:Script>

	<!-- bad -->
	<mx:Button enabled="{(this.arg1) && (this.arg2)}" />

	<!-- good -->
	<mx:Button enabled="{(this.arg1) &amp;&amp; (this.arg2)}" />

	<!-- also good, but more code -->
	<mx:Button enabled="{this.validate()}" />
</mx:Application>