《孙子兵法·虚实篇》
所以要认真分析判断，以求明了敌人作战计划的优劣长短；挑动敌人，以求了解他们的行动规律；示形诱敌，以求摸清其所处地形的有利与不利；进行试探性进攻，以求探明敌人兵力部署的强弱多寡。
故策之而知得失之计，作之而知动静之理，形之而知死生之地，角之而知有余不足之处。故形兵之极，至于无形。
Therefore, it is necessary to meticulously analyze judgment, in order to clearly understand the advantages, disadvantages, strengths and weaknesses of the enemy's combat plans; provoke the enemy, in order to discern the patterns of their actions; demonstrate a form to entice the enemy, in order to ascertain the advantages and disadvantages of the terrain in which they are located; carry out probing attacks, in order to ascertain the strength and weakness of the enemy's troop deployment.