Why doesn't this XPath query work as I assumed? (searching for elements with some @ while excluding those with other @)

I have the following query (XPath 2.0):

//xref[contains(@href,'#') and @class='- topic/xref ' and @type!='step' and @type!='fig' and @type!='substep']

As you can see, I want to find topic/xref elements with a hash in their href attribute. I want to exclude ceratin types of elements. Problem is, the above query does not display elements with @outputclass='expandable'

I had to run a seperate one to identify them:

//xref[contains(@href,'#') and @outputclass='expandable']

Why does the first, longer query, do not display those elements? I also tried contains(@class='- topic/xref ) instead of @class=' - topic/xref ' and it didn't help.

Solution

Try below XPath:

//xref[@class="- topic/xref " and contains(@href, "#") and not(@type=("fig", "substep", "table") or @outputclass="expandable")]

that will return xref elements with class="- topic/xref " and # in href attribute but doesn't have type attribute with values "fig", "substep", "table" or outputclass attribute with value "expandable"