An upapada ending in third case-affix or any other of the remaining four cases, is optionally compounded with a word ending with the affix ktavā and the compound is tat-puruṣa,
This rule provides for avyayas ending in क्त्वा which the last two rules did not provide. Thus we have उच्चैः कृत्य or उच्चैः कृत्वा. Here the affix क्त्वा is added by sutra (III. 4. 59.) In the case when there is composition, the क्त्वा is replaced by the substitute ल्यप् ; otherwise not. See (VII. I. 37).
The condition of the upapadas being in the 3rd case &c., applies here also. Therefore there is no composition in अलं कृत्वा or खलु कृत्वा.,