[Haskell-cafe] Re: Laws and partial values
jonathanccast at fastmail.fm
Sun Jan 25 10:11:08 EST 2009
On Sun, 2009-01-25 at 10:46 +0100, Thomas Davie wrote:
> On 25 Jan 2009, at 10:08, Daniel Fischer wrote:
> > Am Sonntag, 25. Januar 2009 00:55 schrieb Conal Elliott:
> >>> It's obvious because () is a defined value, while bottom is not -
> >>> per
> >>> definitionem.
> >> I wonder if this argument is circular.
> >> I'm not aware of "defined" and "not defined" as more than informal
> >> terms.
> > They are informal. I could've written one is a terminating
> > computation while
> > the other is not.
> Is that a problem when trying to find the least defined element of a
> set of terminating computations?
Yes. If you've got a set of terminating computations, and it has
multiple distinct elements, it generally doesn't *have* a least element.
The P in CPO stands for Partial.
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