Schematron using XPath 2.0 There must be at least one instance where prov:attribute = 'Supersedes'. There must be at least one instance where prov:attribute = 'Reason'. When prov:attribute is 'Supersedes', prov:value must start with 'urn:'. When prov:attribute is 'Reason', prov:value must be one of these values: 'Replacement', 'Duplication', 'Merged', 'Obsolescence', 'Policy'.