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Topic: Sprouts Notation
Replies: 6   Last Post: Jan 19, 1999 4:39 PM

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John Conway

Posts: 2,238
Registered: 12/3/04
Re: Conway Notation
Posted: Jan 19, 1999 3:03 PM
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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 expert-level game
> might end before the outcome would be obvious to every reader. I know
> chess notation uses "1-0" and "0-1" 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

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