anchor.diff:     ;
   
   atom
  -   : STRINGLITERAL
  -   | INTEGER
  +   : (STRINGLITERAL1 | STRINGLITERAL2 | INTEGER)
      | subject
      | command
      | '[' expression (',' expression)* ']'
  
positive.code:    ;
  
  lin
      : line? EOL;
  
  line
     : (label? subject pattern? EQ expression+ (COLON transfer)?)
     | (COLON transfer)
     | COMMENT 
     | END
     ;
  
  label
  
negative.code:    : ':'
     ;
  
  
  END
     : 'END'
     ;
  
  
  STRINGLITERAL1
     : '"' ~ ["\r\n]* '"'
     ;
  
  
  STRINGLITERAL2
     : '\'' ~ [\'\r\n]* '\''
     ;
  
  
  