First, we figure out a new game, G, using the atomic weights of the options of {4|*||*}.
We know that the atomic weight of * is 0, but what is the atomic weight of {4|*}? Let's figure out a new game, H, for it.
Again, the atomic weight of * is 0. And I can tell you that the atomic weight of any number is also 0. Makes sense, right?
So H = {0|0}
But we are not done with H. Now we have to start off like we are cooling H by 2 degrees. That gives us
H
0 = {-2|2} = 0
So far, so good. But that does not mean that the atomic weight of {4|*} is 0. We now have to check whether it is an
eccentric case.
It is an eccentric case iff H
0 is an integer and H is greater than or less than a
far star.
What, you may ask, is a far star? It is a sufficiently big nimber, *N, when N is large enough. When is N large enough? When it is larger than any nimber anywhere in the game tree of H, including H itself.
The largest nimber in {4|*} is * = *1. So *2 is a far star for it. Then we have the question,
{4|*} + {0,*|0,*} <?> 0
OC, Black to play can win by playing to 4 + *2
White to play cannot win by playing in *2, so let him play to * + *2. Then Black replies to * + * = 0 and wins.
That means that H > *2 and we have an eccentric case.
Now we look at the White options of H
0 = {-2|2}. Now we find the largest integer, I, for which I <| 2. The largest integer which is less than or confused with 2 is 1. If there were more White options of H
0 we would look for the largest integer which is less than or confused with all of the White options. If H were less than *2 we would do the opposite for the Black options of H
0.
OK, so the atomic weight of {4|*} is 1. Now we are ready to find the atomic weight of {4|*||*}.
G = {1|0}
G
0 = {-1|2} = 0.
Here we are again.
Well, we know that the far star is *2. We ask,
{4|*||*} + {0,*|0,*} <?> 0
Black, OC, wins by playing to {4|*} + *2, which we know is positive.
If White plays in {4|*||*} to * + *2 Black wins, so let White play in *2. OC, if White plays to {4|*||*}, it is positive, so Black wins. Finally, let White play to * + {4|*||*}; then Black replies in * to {4|*||*} and wins.
So {4|*||*} > *2.
G
0 = {-1|2}
We know that the largest integer, I <|2 is 1.
As we suspected, the atomic weight of {4|*||*} is 1.
Whew!