XSLT expression to check if variable belongs to set of elements

Question

I have code like this:

Is there any way to put this expression in a form, li

Answer 1

XSLT / XPath 1.0:

You can use other separators if needed.

In XSLT / XPath 2.0 you could do something like:

If you can use document structure to define your list, you could do: