anchor.diff:      type writeParentPagesState = 
           { 
               sofar:int; 
  -            first:int;
  -            //items:(int32*byte[]) list; 
  +            items:(int32*byte[]) list; 
               nextPage:int; 
               boundaryPage:int; 
               //children:(int32*byte[]); 
  
positive.code:                         if flushThisPage then
                              // assert sofar > 0
                              let thisPageNumber = nextPageNumber
                              let subList = children |> Seq.skip first |> Seq.take (i - first) |> Seq.toList
                              buildParentPage subList (fst children.[i]) overflows
                              let isRootNode = isLastChild && couldBeRoot
                              let (nextN,nextB) =
                                  if isRootNode then
  
negative.code:                         else
                              let sofar = args.sofar
                              if sofar = 0 then
                                  {args with sofar=PARENT_PAGE_OVERHEAD; items=[]; }
                              else
                                  args
  
  