Up to iḍāyā vā [[8.3.54]], inclusive, should be always supplied in every subsequent sūtra the phrase 'of a word' or 'to the whole of a word'.,
This is an adhikara sutra, and extends up to 8.3.55. Whatever we shall treat of here-after, should be understood to apply to a full 'pada' or a completed word. Thus 8.2.23, (संयोगान्तस्य लोपः) teaches \there is elision of the final of what ends in a conjunct consonant\. The word पदस्य must be supplied here to complete the sense : viz, of a word which ends in a conjunct consonant, the final is elided. Thus पचन्, यजन्, from पचन्त् and यजन्त् ॥
Why do we say 'of a Pada'? Observe पचन्तौ, यजन्तौ where the त् though sanyoganta is not elided, because the stem is no longer called pada. The force of the Genitive in पदस्य must be construed according to the context, sometimes as sthana-shashthi i.e. \in the room of the whole pada\; and sometimes as avayava-shashthi i.e. \of a pada-of the portion of a pada \.,