Wolfgang, can you share failing test? I did fix similar for "and" some time ago, this one should be similar.

On Tue, Apr 30, 2013 at 8:36 PM, <wolfgang@exist-db.org> wrote:
> ERROR cannot convert xs:boolean('true') to a node set

This is actually a bug in the implementation of the "or" operator. I encountered it a few days ago and have a fix on my laptop. It causes a test to fail though and I need to investigate some more.

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Dmitriy Shabanov