On Sun, Apr 08, 2007 at 10:18:10AM +0200, Chrilly wrote: > Paper 1 in the list below states: > Numbers were originally implemented in Lisp I as a list of atoms. > and the Lisp 1.5 manual states: Arithmetic in Lisp 1.5 is new.... > > Could you give an example how the number 3 was implemented in Lisp-1 and > how 2+1?
I don't know, but from the description "list of atoms," perhaps numbers were represented as linked lists of bits (using the facilities built in to support linked lists of anything). > >On Apr 7, 2007, at 12:54 PM, Chrilly wrote: > >>Up to my knowledge the first Lisp Versions had no number system. The > >>number n was represented as the list of numbers from 1 to n (which is > >>also the mathematical/axiomatic definition of the natural numbers). > >>But its not very practical. Can anyone provide me with a link how this > >>was done. I am speaking some computer languages, but Lisp is not among > >>them. > >>I want to present the code in an article for the Austrian AI- Journal (as > >>an example that mathematical elegance and practically usefull are 2 > >>different things). Note how early this was in computer hardware development, and how it didn't take them long (in calendar years) to introduce more efficient representations of numbers. I think quite possibly it was not an instance of people choosing elegance at the expense of practicality, but an instance of practical people imposing very severe limitations on software features because of the hardware limitations of early machines. It wasn't all that far away (in calendar years) from the time when people programmed Chess on a 6x6 board, right? I doubt that that early 6x6 Chess program is good evidence that its computer programmers didn't care about playing Chess by standard rules... -- William Harold Newman <[EMAIL PROTECTED]> PGP key fingerprint 85 CE 1C BA 79 8D 51 8C B9 25 FB EE E0 C3 E5 7C Ubi saeva indignatio ulterius cor lacerare nequit. -- Jonathan Swift's epitaph _______________________________________________ computer-go mailing list computer-go@computer-go.org http://www.computer-go.org/mailman/listinfo/computer-go/
