Re: Proposal: 6NF

From: Marshall <marshall.spight_at_gmail.com>
Date: 10 Oct 2006 20:36:08 -0700
Message-ID: <1160537768.046280.133920@i42g2000cwa.googlegroups.com>

On Oct 10, 5:28 pm, "David Cressey" <dcres..._at_verizon.net> wrote:

> It's not clear to me that the real number 2 is the
> same thing as the integer 2.

This is another one of those questions that can't be separated from its theory. Arithmetically, 2 and 2.0 are identical. Type-theoretically, they might not be. Depending on the particular type system, they might or might not be assignment compatible, or have some kind of subtype relationship.

And what kind of int 2 are we talking about? 8 bit, 16 bit, 32 bit, arbitrary? Signed or unsigned? What size float? It's true the integers are a subset of the reals, but we don't (and mostly can't) have a type that works the same as the reals in a computer. We could say that the 32 bit ints are a subset of double but not of float, etc. etc.

As an aside, I'd love to see a system in which n-bit integer was a single generic definition, instantiated with different values of n. I think it might not actually be too hard to do.

Floating point arithmetic isn't associative. I hate that.

Marshall Received on Tue Oct 10 2006 - 22:36:08 CDT