# What does **MEX** stand for?

## What does **MEX** mean? This page is about the various possible meanings of the acronym, abbreviation, shorthand or slang term: **MEX**.

###
We've found a total of **8** definitions for **MEX**:

**Filter by:**

**Sort by:**PopularityAlphabeticallyCategory

#### What does **MEX** mean?

- Mex
- In combinatorial game theory, the mex, or "minimum excludant", of a set of ordinals denotes the smallest ordinal not contained in the set. Some examples: where ω is the limit ordinal for the natural numbers. In the Sprague-Grundy theory the minimum excluded ordinal is used to determine the nimber of a normal-play impartial game, which is a game in which either player has the same moves in each position and the last player to move wins. The nimber is equal to 0 for a game that is lost immediately by the first player, and is equal to the mex of the nimbers of all possible next positions for any other game. For example, in a one-pile version of Nim, the game starts with a pile of n stones, and the player to move may take any positive number of stones. If n is zero, the nimber is 0. If n is 1, the player to move will leave 0 stones, and the mex of { 0 }, 1, gives the nimber for this case. If n is 2, the player to move can leave 0 or 1 stones, giving 2 as the mex of { 0, 1 }. In general, the player to move with a pile of n stones can leave anywhere from 0 to n-1 stones; the mex of the numbers { 0, 1, ..., n-1 } is always n. From this we can conclude that the first player wins if n is not zero.

**Still can't find the acronym definition you were looking for?** Use our **Power Search technology** to look for more unique definitions from across the web!

"MEX." *Abbreviations.com.* STANDS4 LLC, 2016. Web. 23 Aug. 2016. <http://www.abbreviations.com/MEX>.