> toFList [] = id
> toFList (xs++ys) = toFList xs . toFList ys
>
> toList id = []
> toList (f . g) = toList f ++ toList g
These laws do not *define* the isomorphisms because their behavior on
singletons is not fixed. Combining them with laws using a 'point'
function for functional lists
point = (:)
the isomorphisms are characterized uniquely:
toFList [x] = point x
toList (point x) = [x]
This might be an argument in favor of a Pointed class without Functor
constraint as it shows that other pointed structures have reasonable
laws involving 'point' as well.
Sebastian
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