E4X question

Hello everyone,
I’ve been reading chapter on E4X in Essential AS3
and I’m having trouble understanding this one thing.

var product:XML = <PRODUCTQUANTITY=“1”><COST>1</COST><QUANTITY>1</QUANTITY></PRODUCT>;

//why would this output to true whereas
trace(product.COST.*[0] == product.QUANTITY);

//this one outputs false??
trace(product.COST == product.QUANTITY);

It’s on page 408 if you have the book.

Thank you.