如何在XPath中选择具有一个属性的特定值和另一个属性的最大值的节点？

For example, I have an XML:

例如,我有一个XML:

    <?xml version="1.0"?>
<list>
    <pos matnr="10017571" charg="1045825700" atwrt="108" labst="610" />
    <pos matnr="10017572" charg="1045825700" atwrt="108" labst="600" />
    <pos matnr="10017573" charg="1046186400" atwrt="108" labst="2730" />
    <pos matnr="10017573" charg="1046117000" atwrt="108" labst="5200" />
    <pos matnr="10017573" charg="1046055000" atwrt="108" labst="3507" />
    <pos matnr="10017574" charg="1045911400" atwrt="108" labst="50" />
    <pos matnr="10017574" charg="1046055000" atwrt="108" labst="14230" />
    <pos matnr="10017574" charg="1046117000" atwrt="108" labst="5500" />
    <pos matnr="10017574" charg="1046186400" atwrt="108" labst="2410" />
</list>