anchor.diff:      checkNonNull "resizeArray2" resizeArray2
   
       let len = length resizeArray1
  -    if len = length resizeArray2 then
  +    if len <> length resizeArray2 then
           invalidArg "resizeArray2" "The ResizeArrays have different lengths."
   
       let results = ResizeArray (len)
  
positive.code:         state <- f.Invoke(arr.[i], state)
          res.[i - start] <- state
      res
  
  
negative.code: 
      while index < count && Option.isNone result do
          result <- picker resizeArray.[index]
          index <- index + 1
      result
  
  //
  