Questions tagged [nim]

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A "semi-genetic" definition of addition and multiplication in the field $\operatorname{On}_p$?

Let $+,\cdot$ denote multiplication in $\mathbb{N}_0$. The addition and multiplication in $\operatorname{On}_p$ are denoted $\oplus, \otimes$. Recursive definition of addition: $$x \oplus y := ((x+y) \...
mathoverflowUser's user avatar
1 vote
2 answers
253 views

Do restricted Nim-like games have winning strategies?

Considering a Nim-like game to be: There are three piles $A,B,C$, and the amount of their elements are $|A|=2, |B|=5, |C|=6$; There are 2 players. Each time a player can either take $x (1\leq x \leq ...
Stacker Dragon's user avatar
2 votes
0 answers
271 views

Combining a Nim-variation and Wyrthoff's game. How to find a winning strategy? [closed]

Wythoff's game is a variation of the classical Nim - There are two heaps and the players take turns either taking any amount from one heap, or the same amount of both heaps. The winner is the one ...
Mathematical Layman's user avatar
9 votes
1 answer
365 views

Ordered Nim game

Consider the following variant of Nim: There are two players and $n$ piles of stones, with sizes $a_1,\dots,a_n$, such that $a_i\leq a_j$ for any $i<j$. A move consists of removing a positive ...
Alex Row's user avatar
6 votes
0 answers
328 views

Asymptotic density of winning positions in "Prime Nim"?

Consider a single-pile NIM variant, played under standard (not misere) objective, with the rule that you may remove any prime number from the pile. The winning positions of this game are all numbers $...
Mark Fischler's user avatar
3 votes
1 answer
594 views

Misere nim variant

Is there a name (and strategy) for this nim variant? There are $n$ lists of objects, say $L_1,\ldots,L_n$ where $L_i = \{a_{i,1},a_{i,2},\ldots,a_{i,n_i}\}$. Players take turns choosing a list and ...
user82059's user avatar
3 votes
0 answers
671 views

Nimbers and Surreal Numbers [closed]

I have been researching Combinatorial Game Theory. One common theme is the assignment of values to games in order to classify the game as a win for a specific player. One such way is class of surreal ...
Halbort's user avatar
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5 votes
0 answers
287 views

Generalization of Sprague-Grundy Theorem

In my research on Combinatorial Game Theory, I used a certain theorem that is essentially a generalization of the Sprague-Grundy theorem. Because the result hinges too much on the work of others to be ...
Halbort's user avatar
  • 1,129
15 votes
3 answers
2k views

Why does the bitxor function appear in Nim?

I am conducting research in Combinatorial Game Theory (CGT). Although I have done a considerable amount of reading, I do not completely understand why the bit-xor function also known as the nim-sum ...
Halbort's user avatar
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5 votes
0 answers
210 views

Analysis of Nim-Like Game? [closed]

There are a finite number of heaps, each with a finite number of counters. Two players take turns; on each move, they may remove exactly one counter from any heap, and also, if the heap is of size $n$,...
Mathnerd314's user avatar
6 votes
1 answer
312 views

Anything known about the Grundy Ordinal of Sylver's Coinage

Sylver's coinage is an example of an unbounded finite (if slightly modified) combinatorial impartial game. Quoth wikipedia: The two players take turns naming positive integers that are not the sum of ...
Christopher King's user avatar
11 votes
2 answers
604 views

Nim and the Sierpinski Gasket

(I discovered this in high school, sent it off to a journal, never heard back, and forgot about it. I've never found anyone else who appeared to know about it; the combinatorial game theorists I've ...
Bakkot's user avatar
  • 211
2 votes
2 answers
1k views

Generalized Sprague-Grundy Theorem

Hey, I know what is Sprague-Grundy theorem, but I want to know about generalized Sprague-Grundy (GSG) theorem ( which is used for games with cycles ). Apparently there seems to be very less ...
Pranav Raj's user avatar
2 votes
7 answers
2k views

Nim-like(?) game winning strategy?

I have the following Nim-like game (at least, it seems Nim-like to me). There are $2k$ tokens in a row, $k \in \mathbb{N}$. Each token $a_i$ has a value $ v_i \in \mathbb{N}$ All this information ...
Shaywei's user avatar
  • 163
3 votes
1 answer
3k views

The game of "nimble" with no stacking

The game of Nimble is played as follows. You have a game board consisting of a line of squares labelled by the nonnegative integers. A finite number of coins are placed on the squares, with possibly ...
Michael Lugo's user avatar
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