Hello i want to ask what exactly this Xpath does if we use.

I understand that it selects all b nodes that appear before the current node and that are not the same with current node.

```
//b[not(preceding::*=.)]

```

So if xml is like:

```
<a>
 <b>English</b>
 <b>German</b>
 <b>Italian</b>
 <b>Belarusian</b>
 <b>Russian</b>
 <b>Bulgarian</b>
 <b>French</b>
 <b>English</b>
</a>

```

Does this keep the last occurrence of the node or the first? this is what i do not get. 

I was thinking that it should keep the last but using this xpath in FILTERXML function i gives the result of keeping the first occurrence so the result was 

{"English";"German";"Italian";"Belarusian";"Russian";"Bulgarian";"French"}

Can someone explain?