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Re: Conway Notation
Posted:
Jan 19, 1999 3:03 PM


On 19 Jan 1999, Danny Purvis wrote:
> Thanks, Dr. Conway. I agree completely with your improvements. I expected some argument!
> I think the new notation likely could be decoded by a player unequipped > with an explicit explanation. I will translate my analysis of sprouts > through n=7 (my message entitled "Sprouts Notation  Examples") into > the new notation, though I might wait a few days to see if anyone > finds any errors.
Forgive me for saying that I can hardly believe that you could have a complete analysis of n=7. > I do have two questions. (1) Do I understand correctly that you now > prefer spaces only, rather than ";" or ",", to separate moves?
I'm not fussy about this.
> (2) Do I understand correctly that we are dropping the ":X" and ":Y"?
No  I wasn't expressing an opinion on this  but if you ask me for one I'll say that I prefer "I" and "II", which are used by the theoreticians of infinite games.
> If so, could you suggest a replacement? I think often an expertlevel game > might end before the outcome would be obvious to every reader. I know > chess notation uses "10" and "01" to indicate wins by the first > player and second player respectively. Perhaps that convention should > be borrowed?
Could do.
You didn't say which version you were adopting. Let me suggest the parenthesis one, so 1(7@6)2 means that spot 7 is being placed on a new line drawn from 1 to 2, in such a way that it's accessible from 6.
Then I see I'm not sure what's the best way to indicate the separations. Really subscripts would be nicest  for instance
1 (7) 2 3 4&5
would mean that this line separates 3 from 4&5  but this is hard by email. How about
1(3\7/4&5)2 for this, and 1(3\7@6/4&5)2
to make the further assertion that 7's to be accessible from 6? Of course this is complicated, but only much simpler cases are likely to be used.
Of course 1(7/3)5 would mean that the new line separates 3 from everything it CAN be separated from.
The Chess notation of ! and ? for moves we regard as good and bad, seems a nice one.
John Conway



