Hello-

Is there standard function in Haskell that effectively does an inverse scan? For example,

scanl1 (\ x y -> x+y) [1,2,3,4] == [1,3,6,10].

So is there a very simple built-in way to do this hypothetical example?:

unscanl1 (\ x y -> y-x) [1,3,6,10] == [1,2,3,4]

Thanks,
Jeffrey