anchor.diff:  
   PNAME_LN : PNAME_NS PN_LOCAL;
       
  -BLANK_NODE_LABEL : '_:' PN_LOCAL;
  +BLANK_NODE_LABEL : '_:' (PN_CHARS_U|DIGIT) ((PN_CHARS|DOT)* PN_CHARS)?;
   
   VAR1 : '?' VARNAME;
   
  
positive.code:     | '\u3001'..'\uD7FF'
      | '\uF900'..'\uFDCF'
      | '\uFDF0'..'\uFFFD'
      ;
  
  fragment
  PLX : PERCENT | PN_LOCAL_ESC;
  
  fragment
  
negative.code:     
  SEPARATOR : ('S'|'s')('E'|'e')('P'|'p')('A'|'a')('R'|'r')('A'|'a')('T'|'t')('O'|'o')('R'|'r');
  
  IRIREF
      : '<' (~('<' | '>' | '"' | OPEN_CURLY_BRACE | CLOSE_CURLY_BRACE | PIPE | INVERSE | '`' | '\\' | '\u0000'..'\u0020'))* '>'
      ;
  
  