Re: [OT] Algebra (was: Re: Is Concatenation that complex?)
Re: [OT] Algebra (was: Re: Is Concatenation that complex?)
- Subject: Re: [OT] Algebra (was: Re: Is Concatenation that complex?)
- From: Clark Cox <email@hidden>
- Date: Fri, 23 Apr 2004 12:32:45 -0400
On Apr 23, 2004, at 11:36, David Blanton wrote:
>
On 4/23/04 8:10 AM, "Kay Roepke" <email@hidden> wrote:
>
>
> On 23. Apr 2004, at 10:40 Uhr, Marco Scheurer wrote:
>
>
>
>> In my book "+" is used for, among other properties, commutative
>
>> operations. Here a+b is not the same as b+a.
>
>
>
> Yeah...strings are obviously members of left- resp. right-modules
>
> rather than of vectorspaces.
>
> Aah, well...those were good times ;-)
>
>
>
> Kay
>
>
>
+ is only commutative over certain sets ...
>
Consider matrix addition where A + B != B + A !
Matrix addition is both commutative and associative. (You may have been
thinking of matrix multiplication)
See: <
http://mathworld.wolfram.com/MatrixAddition.html>
--
Clark S. Cox III
email@hidden
http://homepage.mac.com/clarkcox3/
http://homepage.mac.com/clarkcox3/blog/B1196589870/index.html
[demime 0.98b removed an attachment of type application/pkcs7-signature which had a name of smime.p7s]
_______________________________________________
cocoa-dev mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/cocoa-dev
Do not post admin requests to the list. They will be ignored.