Kautilya's Arthashastra 10.6.2

10.6.2

pakṣau kakṣāv urasym pratigraha iti bārhasptyaḥ //

WINGS and front, capable to turn (against an enemy is what is called) a snake-like array (bhoga); the two wings, the two flanks, the front and the reserve (form an array) according to the school of Brihaspati. The principal forms of the array of the army, such as that like a staff, like a snake, like a circle, and in detached order, are varieties of the above two forms of the array consisting of wings, flanks and front.