anchor.diff:    ;
   */
   
  -// original  : '"' (~ ["\\\r\n] | '\'' | '\\"')* '"'
  +
  +// TURTLE.g4 says  '"' (~ ["\\\r\n] | '\'' | '\\"')* '"'
  +// but the one below is what is written in https://www.w3.org/TR/turtle/#grammar-production-STRING_LITERAL_QUOTE
   STRING_LITERAL_QUOTE
     : '"' (~ ["\\\r\n] | ECHAR |  UCHAR)* '"'
     ;
  
positive.code:   : PERCENT | PN_LOCAL_ESC
    ;
  
  PERCENT // ok
    : '%' HEX HEX
    ;
  
negative.code:   : [0-9] | [A-F] | [a-f]
    ;
  
  // reserved character escape sequences for local names only
  PN_LOCAL_ESC  // ok
    : '\\' ('_' | '~' | '.' | '-' | '!' | '$' | '&' | '\'' | '(' | ')' | '*' | '+' | ',' | ';' | '=' | '/' | '?' | '#' | '@' | '%')
    ;
  