只有一个匹配的E4X条件调用不会返回任何东西?

ok here is my code:

这是我的代码:

var xml:XML = 
<xml>
    <typeA amount1="500" amount2="300" amount3="250" date="2008-02-17"/>
    <typeA amount1="500" amount2="300" amount3="250" date="2008-02-16"/>
    <typeA amount1="500" amount2="300" amount3="250" date="2008-02-17"/>
    <typeB amount1="500" amount2="300" amount3="250" date="2008-02-18"/>
    <typeB amount1="500" amount2="300" amount3="250" date="2008-02-19"/>
    <typeC amount1="500" amount2="300" amount3="250" date="2008-02-20"/>
    <typeC amount1="500" amount2="300" amount3="250" date="2008-02-21"/>
    <typeC amount1="500" amount2="300" amount3="250" date="2008-02-20"/>
</xml>;


trace(xml.typeA.(@date == "2008-02-16")); // no results
trace(xml.typeA.(@date == "2008-02-17")); // finds both
trace(xml.typeC.(@date == "2008-02-20")); // finds both
trace(xml.typeC.(@date == "2008-02-21")); // no results
var xml:XML =