anchor.diff:  typeDeclaration throws XPathException: 
   	"as"^ sequenceType ;
   
  +// === Types ===
  +	
   sequenceType throws XPathException
   :
  -	( "empty" LPAREN ) => "empty"^ LPAREN! RPAREN! | itemType ( occurrenceIndicator )?
  +	( "empty" LPAREN ) => "empty"^ LPAREN! RPAREN! | itemType ( occurrenceIndicator )?  // deprecated
  +	// conformant: ( "empty-sequence" LPAREN ) => "empty-sequence"^ LPAREN! RPAREN! | itemType ( occurrenceIndicator )?
   	;
   
   occurrenceIndicator
  
positive.code: 
  itemType throws XPathException
  :
  	( "item" LPAREN ) => "item"^ LPAREN! RPAREN! | ( . LPAREN ) => kindTest | atomicType
  	;
  
  singleType throws XPathException
  
negative.code: 	"rename" exprSingle "as"! exprSingle
  	;
  
  // === FLOWER ===
  	
  flworExpr throws XPathException
  :
  	( forClause | letClause )+ ( "where" expr )? ( orderByClause )? "return"^ exprSingle
  