Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-26 Thread Nils Anders Danielsson
On Sat, 24 Jun 2006, Paul Hudak [EMAIL PROTECTED] wrote: Hmmm... never tried to write all this down in one place before, but I think this covers all cases: A partial list is one that ends in _|_. A total list is one that ends in []. A finite list is either partial or total. Any other list

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-24 Thread Paul Hudak
Stepan Golosunov wrote: 1:_|_ is certainly finite. And what is length _|_ ? _|_, of course!! :-) The point being, length is well-defined only for total lists; it is undefined for partial lists. But this doesn't mean that a partial list isn't finite. What is finite list then? Is ones =

[Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread Jerzy Karczmarczuk
Paul Hudak wrote: Actually Brian's intuition is right on target. One way to define an infinite list is as the limit of an infinite chain of partial lists (which, in domain theory, is essentially how all elements are defined). as the answer to Brian Hulley conjecture criticized by myself:

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread Paul Hudak
Jerzy Karczmarczuk wrote: OK, I think that this subject matured enough to rest in peace... I would have to agree with that, although... Couldn't an infinite list just be regarded as the maximum element of the (infinite) set of all finite lists? Perhaps his intuition is right, but there are

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread Bill Wood
On Fri, 2006-06-23 at 09:38 -0400, Paul Hudak wrote: . . . But the limit of a chain IS the maximal element of the set of all elements comprising the chain, since the LUB, in the case of a chain, is unique, and thus we don't have to worry about choosing the least element (i.e. it reduces

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread voigt . 16734551
--- [EMAIL PROTECTED] wrote: Jerzy Karczmarczuk wrote: OK, I think that this subject matured enough to rest in peace... I would have to agree with that, although... Since the subject is not going to rest, why not also jump in? Well, each partial list is finite. I think quite a few

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread Paul Hudak
Bill Wood wrote: On Fri, 2006-06-23 at 09:38 -0400, Paul Hudak wrote: But the limit of a chain IS the maximal element of the set of all elements comprising the chain, since the LUB, in the case of a chain, is unique, and thus we don't have to worry about choosing the least element (i.e. it

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread Paul Hudak
[EMAIL PROTECTED] wrote: Well, each partial list is finite. I think quite a few people would agree that a finite list is one ending in []. So 1:_|_ is a partial list, but not a finite one. 1:[] is a finite list. 1:_|_ is certainly finite. In what sense is it not? That doesn't quite make

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread voigt . 16734551
--- [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote: 1:_|_ is certainly finite. In what sense is it not? I see that point. I have been using finite as, by convention, equal to total and finite. And so have others. As always with convention, one can argue. I won't, of course. Sorry, see my

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread Stepan Golosunov
On Fri, Jun 23, 2006 at 10:57:48AM -0400, Paul Hudak wrote: [EMAIL PROTECTED] wrote: Well, each partial list is finite. I think quite a few people would agree that a finite list is one ending in []. So 1:_|_ is a partial list, but not a finite one. 1:[] is a finite list. 1:_|_ is

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread Stefan Holdermans
Stepan, And what is length _|_ ? _|_ Regards, Stefan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread Paul Hudak
Stepan Golosunov wrote: On Fri, Jun 23, 2006 at 10:57:48AM -0400, Paul Hudak wrote: [EMAIL PROTECTED] wrote: I think quite a few people would agree that a finite list is one ending in []. So 1:_|_ is a partial list, but not a finite one. 1:[] is a finite list. 1:_|_ is certainly finite. In

Re: [Haskell-cafe] Re: Functional progr., infinity, and the Universe

2006-06-23 Thread Stepan Golosunov
On Fri, Jun 23, 2006 at 03:30:18PM -0400, Paul Hudak wrote: Stepan Golosunov wrote: On Fri, Jun 23, 2006 at 10:57:48AM -0400, Paul Hudak wrote: [EMAIL PROTECTED] wrote: I think quite a few people would agree that a finite list is one ending in []. So 1:_|_ is a partial list, but not a