[Haskell-cafe] Re: instance Eq (a -> b)

[Thomas Davie]

On 14 Apr 2010, at 09:08, Jonas Almström Duregård wrote:

>> f,g :: Bool -> Int
>> f x = 6
>> g x = 6
>> 
>> We can in Haskell compute that these two functions are equal, without solving the halting problem.
> 
> Of course, this is the nature of generally undecidable problems. They
> are decidable in some cases, but not in general.

Well yes, but we already knew that this was true of function equality – we can't tell in general.

Bob