hi, python 2.7, lxml2.3, freebsd amd64 I'm using lxml to validate against the DocBook v5 relaxng schema. I get an error that says "Expecting element set, got chapter, line 2", but the actual schema seems to allow chapters to be starting elements; I've appended the relevant snippets below. First, my test code: --------------------------- from lxml import etree tree = etree.parse('dbtest.xml') relaxng = etree.RelaxNG(file='/path_to/DocBook/V5.0/rng/docbookxi.rng') relaxng.assertValid(tree) --------------------------- results in: File "lxml.etree.pyx", line 3006, in lxml.etree._Validator.assertValid (src/lxml/lxml.etree.c:125415) lxml.etree.DocumentInvalid: Expecting element set, got chapter, line 2. the dbtest.xml starts out with this line: --------------------------- <chapter xmlns="http://docbook.org/ns/docbook" xmlns:xl="http://www.w3.org/1999/xlink" version="5.0"> --------------------------- As far as I can tell, the rng says chapters are okay. The first bit of the rng: <start> <choice> <choice> <ref name="db.set"/> <ref name="db.book"/> <ref name="db.divisions"/> <ref name="db.components"/> etc. and later on db.components is defined: <define name="db.components"> <choice> <choice> <ref name="db.dedication"/> <ref name="db.acknowledgements"/> <ref name="db.preface"/> <ref name="db.chapter"/> etc. thanks for reading. Is this a bug? --Tim Arnold