anchor.diff:          // cannot be captured by a closure.
           let cur = ref -1
           let keys:byte[][] = (Array.ofSeq pairs.Keys)
  -        let sortfunc x y = ByteComparer.Compare(x, y)
  +        let sortfunc x y = ByteComparer.Compare x y
           Array.sortInPlaceWith sortfunc keys
   
           let rec search k min max sop le ge = 
  
positive.code:             ok
  
          let rec searchInParentPage k (ptrs:uint32[]) (keys:byte[][]) (i:uint32) :uint32 =
              let cmp = ByteComparer.Compare (k, keys.[int i])
              if cmp>0 then
                  searchInParentPage k ptrs keys (i+1u)
              else
  
negative.code:                 i <- i + 1
          if i>len then result else (xlen - ylen)
  
      let CompareWithin (x:byte[]) off xlen (y:byte[]) =
          let ylen = y.Length
          let len = if xlen<ylen then xlen else ylen
          let mutable i = 0
  