[Haskell-cafe] Re: ANN: data-category, restricted categories

Ashley Yakeley ashley at semantic.org
Tue Mar 30 19:03:36 EDT 2010

wagnerdm at seas.upenn.edu wrote:
> I believe I was claiming that, in the absence of undefined, Nothing and 
> Nothing2 *aren't* isomorphic (in the CT sense).

Well, this is only due to Haskell's difficulty with empty case 
expressions. If that were fixed, they would be isomorphic even without 

Ashley Yakeley

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