anchor.diff:  :
   	decl:"declare"! "variable"! DOLLAR! varName=qName! ( typeDeclaration )?
   	(
  -		LCURLY! ex:expr RCURLY!
  +		LCURLY! ex:expr RCURLY! // deprecated
  +		// conformant: COLON! EQ! ex:expr
   		|
   		"external"
   	)
  
positive.code: 	COMP_DOC_CONSTRUCTOR
  	;
  
  xpointer throws XPathException
  :
  	"xpointer"^ LPAREN! ex:expr RPAREN!
  
negative.code: 	{ #atomicType= #[ATOMIC_TYPE, name]; }
  	;
  
  // === Expressions ===
  	
  queryBody throws XPathException: expr ;
  
  expr throws XPathException
  