anchor.diff:      ;
   
   importElement
  -    : 'implicit'? importAlias? importedName
  -    -> ^(IMPORT_ELEM 'implicit'? importAlias? importedName)
  +    : IMPLICIT? importAlias? importedName
  +    -> ^(IMPORT_ELEM IMPLICIT? importAlias? importedName)
       ;
   
   importWildcard
  
positive.code:     ;
  
  switchHeader
      : 'switch' '(' expression ')'
      -> ^(SWITCH_EXPR expression)
      ;
  
  cases 
  
negative.code:     ;
  
  forBlock
      : 'for'^ '('! forIterator ')'! block
      ;
  
  failBlock
      : 'fail'^ block
      ;
  
  forIterator
  