anchor.diff:      ;
   
   boolean_literal
  -    :   { "true".equals(input.LT(1).getText()) }? TRUE
  -    |   { "false".equals(input.LT(1).getText()) }? FALSE
  +    :   { "true".equals(_input.LT(1).getText()) }? TRUE
  +    |   { "false".equals(_input.LT(1).getText()) }? FALSE
       ;
   
   selector
  
positive.code:     |   CHARACTER_LITERAL
      |   STRING_LITERAL
      |   boolean_literal
      |   { "null".equals(input.LT(1).getText()) }? NULL
      ;
  
  integer_literal
  
negative.code:     ;
  
  else_statement
      :   { "else".equals(_input.LT(1).getText()) }? ELSE java_statement
      ;
  
  switch_block_statement_groups
  