Fix syntax error in the RELAX NG Compact schema in `propertyAttr`

[domel]

Problem

The RELAX NG Compact schema currently contains a syntax error in the definition of propertyAttr.

The problematic fragment is:

propertyAttr =
  attribute * - ( local:* | rdf:RDF | rdf:ID |
                  rdf:annotation | rdf:annotationNodeID |
                  rdf:about | rdf:parseType |
                  rdf:resource | rdf:nodeID | rdf:datatype | rdf:version |
                  rdf:li | its:dir | | its:version
                  rdf:Description | rdf:aboutEach |
                  rdf:aboutEachPrefix | rdf:bagID |
                  xml:* ) {
      string
  }

There is an extra | between its:dir and its:version:

rdf:li | its:dir | | its:version

This makes the RELAX NG Compact schema syntactically invalid.

Expected behavior

The RELAX NG Compact schema should be parseable as valid RNC.

Suggested fix

Remove the extra | and ensure that the exclusion list is syntactically valid, for example:

rdf:li | its:dir | its:version |
rdf:Description | rdf:aboutEach |

or reformat the exclusion list to make this kind of typo easier to detect.

[TallTed]

... ensure that the exclusion list is syntactically valid, ... or reformat the exclusion list to make this kind of typo easier to detect.

I like the idea of doing both, i.e., replacing the or above with an and.

I think the existing situation counts as an erratum, albeit one not previously reported, and while resolving that erratum would be most simply done by replacing the | | with |, minor reformatting would both prevent future such errors and make the RELAX NG Compact schema easier for humans to parse, which I think itself a worthy end.