anchor.diff:  INTERFACE
       :   'interface'
       ;
  -    
  +
  +LOCAL
  +    :   'local'
  +    ;
  +
   NONE
       :   'none'
       ;
  
positive.code:     ;
  
  memberType
      : type | 'void'
      ;
  
  memberParameters
  
negative.code:     ;
  
  variable
      : (type|'local') memberName
      ;
  
  //special rule for syntactic predicate
  