[Haskell-cafe] Limits of deduction

[Duncan Coutts]

On Fri, 2007-05-11 at 12:10 +0100, Andrew Coppin wrote:
> Suppose I have you the source code to some arbitrary function that takes 
> a list and returns another list.
> 
> It is possible to determine whether the function always examins the 
> entire input list?

Presumably you mean in the case that you examine the entire output list,
or do you mean when you only examine the output enough to see if it's a
[] or (:) (i.e. to WHNF) ?

Duncan