Praudhamanorama p130

p130

On "dvistriścaturiti kṛtvo'rthe" (Pā. Sū. 8.3.43): Here, by companionship with dvi and tri which end in suc, the word catur also would be taken as ending in suc alone. The mention of "kṛtvo'rthe" is an indicator that "companionship is not everywhere determinative". By this, in "dīdhīvevīṭām" (Pā. Sū. 1.1.6), despite companionship with verbal roots, the augment iṭ is taken. And this is an option in both cases: where it was applicable in the case of catur by "idudupadhasya—" (Pā. Sū. 8.3.41), and where it was not applicable in the case of the other two. Nor should it be suspected that for those two also it is established by "isusoḥ sāmarthye" (Pā. Sū. 8.3.44), because the affix is and that which is meaningful are comprehended there.
In "catuṣkapālaḥ": ṣa is obligatory by "idudupadhasya" (Pā. Sū. 8.3.41).
On "vyapekṣāvirahe'pi" (even in the absence of mutual dependency): the meaning is, in examples such as "tiṣṭhatu sarpiṣkuṇḍikām ānaya" (let it stay; bring the pot of clarified butter).
On "vyapekṣāyām" (when there is mutual dependency): the meaning is, in "idaṃ sarpiḥ kuṇḍikāyāḥ" (this is the clarified butter of the pot). As for what the Pārāyaṇikas said: "The listing of sarpiṣkuṇḍikā etc. among the kaskādi group is for the sake of ṣa-substitution even when residing in the subsequent member"—that is to be disregarded because of conflict with the Mahābhāṣya.