anchor.diff:      ;
   
   elementType
  -    : type
  +    : type_
       ;
   
   //PointerType = "*" BaseType .
   //BaseType    = Type .
   pointerType
  -    : '*' type
  +    : '*' type_
       ;
   
   //InterfaceType      = "interface" "{" { MethodSpec ";" } "}" .
  
positive.code: 
  //TypeSpec     = identifier Type .
  typeSpec
      : IDENTIFIER type
      ;
  
  
  
negative.code: 
  //Conversion = Type "(" Expression [ "," ] ")" .
  conversion
      : type_ '(' expression ','? ')'
      ;
  
  eos
  