Makes sense. That's how Black first wins in ↑*.Gérard TAILLE wrote:Here is a theoritical question on infinitesimals.
Firstly we know that we have ↑ || * and it may be difficult to compare a move in ↑ and a move in *. However we know also that the atomic weight of ↑ is equal to 1 and the atomic weight of * is equal to 0. As a consequence it may seem preferable for black to play in * rather that ↑ in order to not lose this atomic weight of 1.
But infinitesimals can be tricky. In ↑* the Black play to ↑ reverses to 0, for instance.
Not so special, outside of go. All nim games have that property.Gérard TAILLE wrote:Secondly we know that * is a special infinitesimal with the property * + * = 0.
Well, *2 = {0,*|0,*} exists in chilled go. See https://senseis.xmp.net/?MoreInfinitesimalsGérard TAILLE wrote:Taking a game G made of infinitesimals we can thus always assume that we have only 0 or 1 * in the game (the other * being miai).
Also, * can be hidden. For instance, the corridor one longer than ↑ is ↑↑*, but you can't see the *. Also, there is a * in {4|*||*} that is not obvious.
Edited for clarity because I may have misunderstood you:Gérard TAILLE wrote:Now is my question : Assume a game G + ↑ + * and, because I add here an *, assume there are no * in G. In this context (no * in G) can we say that a black move in * dominates a black move in ↑ ?
If, accounting for hidden *s, there is an odd number of *s in G, given ↑*, then the Black move in the ↑ to * is correct, because the * adds to the *s in G to equal 0. Otherwise, you have to take the * into account. If all that is left is ↑*, then the play by Black in the * to ↑ is correct. Domination in CGT is a stronger concept. I believe.