[Haskell-beginners] function - argument termination problem

[Magnus Therning]

2009/9/2 Γιάννης Μαντζουράτος <giannismantz at gmail.com>:
> Hello,
>
> Is it possible to implement in haskell a function f (A) such that if A
> does not ever terminate then f always terminates, and if A always
> terminates then f does not ever terminate? I've been thinking it for a
> while, with no results unfortunately. the actual problem is that i can
> think of no way to force both ifs: a function that always terminates
> independently from its argument could be f (a) = 1, and a function
> that does not terminate even if its argument terminates could be: f
> (a) = f (a + 1), but i can't figure out a "hybrid" version... Is there
> any idea on this?
>
> Thanks in advance :-),

Isn't this the halting problem?

/M

-- 
Magnus Therning                        (OpenPGP: 0xAB4DFBA4)
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