anchor.diff:  //Support "T x in arg" in positional argument lists
   //Note that we don't need to support this yet
   specialArgument
  -    : variableType memberName (containment | specifier)
  -    -> ^(SPECIAL_ARG variableType? memberName containment? specifier?)
  +    : inferrableType memberName (containment | specifier)
  +    -> ^(SPECIAL_ARG inferrableType memberName containment? specifier?)
       //| isCondition
       //| existsCondition
       ;
  
positive.code: memberDeclaration
      : 'assign' memberName block
      -> ^(ATTRIBUTE_SETTER memberName block)
      | memberType memberName
        ( 
          memberParameters methodDefinition
        -> ^(METHOD_DECL memberType memberName memberParameters methodDefinition?)
        | attributeDefinition 
        -> ^(ATTRIBUTE_DECL memberType memberName attributeDefinition?)
        | memberBody
        -> ^(ATTRIBUTE_GETTER memberType memberName memberBody)      
        )
      ;
  
  memberType
      : type | 'void' | 'local'
      ;
  
  memberParameters
      : 
          typeParameters? 
          formalParameters+ 
  
negative.code: blockDeclarationsAndStatements
      : controlStructure blockDeclarationsAndStatements?
      | directiveStatement
      | (specificationStart) => specificationStatement blockDeclarationsAndStatements? //note: the syntactic predicate here is not really necessary, we could move this alt down into the final alt
      | (annotatedDeclarationStart) => annotatedDeclaration blockDeclarationsAndStatements?
      | expression 
      (
  