anchor.diff:  /*
   * Visual Basic 6.0 Grammar for ANTLR4
   *
  -* This is an approximate grammar for Visual Basic 6.0 and the parser at
  +* This is a grammar for Visual Basic 6.0 and the parser at
   * https://github.com/uwol/vb6parser. The grammar is derived from the 
   * Visual Basic 6.0 language reference 
   * http://msdn.microsoft.com/en-us/library/aa338033%28v=vs.60%29.aspx 
  
positive.code:    | NOT
     | NOTHING
     | NULL
     | ON
     | OPEN
     | OPTIONAL
  
negative.code:    ;
  
  OBJECT 
     : O B J E C T
     ;
  
  ON
     : O N
  