[Haskell-cafe] Re: Couple of formal questions
Michael Karcher
usenet at mkarcher.dialup.fu-berlin.de
Thu May 1 11:58:43 EDT 2008
Wouter Swierstra <wss at cs.nott.ac.uk> wrote:
> Hi Creighton,
> > Where could I find a proof that the initial algebras & final
> > coalgebras of CPO coincide? I saw this referenced in the
> > "Bananas.." paper as a fact, but am not sure where this comes from.
> I couldn't find the statement you are referring to in "Functional
> Programming with Bananas, Lenses, Envelopes, and Barbed Wire" - but
> I'm not sure if this holds for every CPO.
Probably he was referring to the last paragraph of the introduction:
Working in CPO has the advantage that the carriers of intial algebras
and final co-algebras coincide, thus there is a single data type that
comprises both finite and infinite elements.
Regards,
Michael Karcher
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