anchor.diff:  
   functionalArgumentDefinition
       : ( (formalParametersStart) => formalParameters )? 
  -      ( block | parExpression /*| literal | specialValue*/ )
  +      (block | parExpression)
       ;
   
   //Support "T x in arg" in positional argument lists
  
positive.code:         extendedType?
          satisfiedTypes?
          typeConstraints?
          classDefinition
      ;
  
  classDefinition
      : classBody | typeSpecifier? ';'!
      ;
  
  classBody
  
negative.code:     -> ^(ATTRIBUTE_SETTER memberName block)*/
  
  objectArgument
      : 'object' parameterName extendedType? satisfiedTypes? classBody
      -> parameterName ^(OBJECT_ARG parameterName extendedType? satisfiedTypes? classBody)
      ;
  
  voidMethodArgument
      : 'void' parameterName formalParameters+ block
      -> parameterName ^(METHOD_ARG 'void' parameterName formalParameters+ block)
      ;
  
  typedMethodOrGetterArgument
      : inferrableType parameterName
      ( 
        (formalParameters+ memberBody)
      -> parameterName ^(METHOD_ARG inferrableType parameterName formalParameters+ memberBody)
      | memberBody
      -> parameterName ^(ATTRIBUTE_ARG inferrableType parameterName memberBody)      
      )
  