[oXygen-user] Can't bind attribute

Hi, I've this situation : file.xml: <effectiveTime xsi:type="PIVL_TS" operator="A"> file.sch: <assert test="child::cda:effectiveTime[position()=1]/@xsi:type='IVL_TS'"> error </assert> Testing with the other attribute (operator) works. I've defined in file.sch: <ns prefix="xsi" uri="http://www.w3.org/2000/10/XMLSchema-instance"/> How can I bind xsi:type attribute? Thanks in advance, bye