anchor.diff:  memberDeclaration
       : voidMethod | methodOrGetter | setter
       ;
  -    
  +
  +//TODO: we would not really need the syntactic predicate
  +//here if we leave off recognizing methods vs. attributes
  +//until later
   methodOrGetter
       : type memberName ( (typeParameterStart | formalParameterStart) => methodDefinition | attributeDefinition )
       ;
  
positive.code:     ;
  
  forIterator
      : formalParameter 'in' expression
      ;
      
  doWhile
  
negative.code:     ;
      
  positionalArguments
      : '(' ( (specialStart) => special | (assignable (',' assignable)*)? ) ')'
      ;
  
  special
      : regularType memberName (containment|specifier)
      ;
  
  specialStart
      : regularType memberName ('in'|'=')
      ;
  
  formalParameters
  