anchor.diff:   */
   
   /*
  -    This grammar is adapted from https://github.com/antlr/grammars-v4/tree/master/turtle,
  -    derived in turn from http://www.w3.org/TR/turtle/#sec-grammar-grammar,
  -    with the following copywright:
  -*/
  -/*
  + This grammar is adapted from https://github.com/antlr/grammars-v4/tree/master/turtle,
  + derived in turn from http://www.w3.org/TR/turtle/#sec-grammar-grammar,
  + with the following copywright:
  +
    [The "BSD licence"]
    Copyright (c) 2014, Alejandro Medrano (@ Universidad Politecnica de Madrid, http://www.upm.es/)
    All rights reserved.
  
positive.code: base
    : ('@base' | '@BASE') iriref
    ;
  
  //prefix
  //  : ('_'? NAME_SBS)? ':'
  //  ;
  
  triples
    : subject  predicateObjectList
  
negative.code:   : 'true' | 'TRUE' | 'True' | 'false'| 'FALSE'| 'False'
    ;
  
  IRIREF
    : '<' (STRING_WITH_CURLY_BRACKET | (PN_CHARS | '.' | ':' | '/' | '\\' | '#' | '@' | '%' | '&' | UCHAR)*) '>'
    ;
  