1) US neighbor 2) Arizona neighbor 3) Born in Baja, perh 4) Chihuahua loc 5) Combinatorial game theory 6) NA nation 7) Neighbor of USA 8) Oaxaca loc 9) Tex follower 10) USA neighbor Found on https://www.crosswordclues.com/clue/mex
[mathematics] 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 ... Found on http://en.wikipedia.org/wiki/Mex_(mathematics)