Square array is a kind of formation used by ancient troops in combat, which is to arrange troops in a square formation on an open field. The ancient phalanx consists of the former army, the middle army and the rear army nested with each other. The plane of the phalanx is in the shape of "Hui", which reflects a political and geographical structure in ancient concepts and comes from the world view of "the sky is round and the place is round".

Mathematically, an n×n matrix is called an n-order square matrix, that is, a square matrix has as many rows as columns.

The theme of Sun Bin's The Art of War;

Sun Bin's military thoughts are mainly concentrated in Sun Tzu's Art of War. Sun Bin pays special attention to pottery, which is similar to the Six Pagodas. In Sun Bin's The Art of War, Sun Bin repeatedly emphasized the role of Taoism in governing the country, the army and defending the enemy.

Sun Bin is not superstitious about the role of rewards and punishments, and thinks that only by "choosing people for their nature" can behaviors flow. If it goes against human nature, rewards and punishments will lose their function. Sun Bin said, "It's useless to reward those who don't do it, but those who listen to the people's orders can do it.

Reward the high and punish the low, but the people don't listen to their orders, and they can't do their orders. Meng is difficult to kill people, although it is unfavorable, it is to blame people for pouring water backwards. "Compared with the role of superstitious rewards and punishments, Sun Bin has a deeper insight.