[Haskell-beginners] Re: Restricting integers in a type?

[Colin Paul Adams]

>>>>> "Ertugrul" == Ertugrul Soeylemez <es at ertes.de> writes:

    >> That would seem to allow x = -3 and y = 13, for instance.

    Ertugrul> Not if you disallow an x = -3 and y = 13 to happen in
    Ertugrul> the first place.  Haskell's module and type system
    Ertugrul> allows you to do that.

Can you explain how to do that please?
-- 
Colin Adams
Preston Lancashire