因明入正理論疏 2.40

2.40

述曰：下別牒結能立。文勢有四，此文初也。牒前宗後指法云「如有成立聲是無常」者，此是所諍立宗之言。

The commentary says: Below, it takes up each individually to conclude the proof. The text has four parts; this is the first. Taking up the previous thesis, it then points out the rule, saying, 'For instance, establishing sound as impermanent'—this is the statement setting forth the thesis under dispute.