In the example in Section 3.4.3.1 the incorrect syntax ':=' is used in the map. Where it should be just a colon (i.e. ':').

Snippet taken from section 3.4.3.1:

 'publisher' := 
       function($n as document-node()) as xs:string? { () } 

Should be:

 'publisher' : 
       function($n as document-node()) as xs:string? { () }