Jha-lānam iy’-uvā sare vā

1. Tiyantaṃ = ti + antaṃ (‘i’ of ‘ti’ is named ‘jha’ (§58); ‘i’ is substituted by ‘iya’ (§70); ‘a’ of ‘iya’ is elided (§83)).
2. Bhikkhuvāsane = bhikkhu + āsane (‘u’ of “bhikkhu” is named ‘la’ (§58); ‘u’ is substituted by ‘uva’ (§70); ‘a’ of ‘uva’ is elided (§83)).
3. The formation of the rest of the examples is similar to the previous ones.

What is the purpose of saying “when a vowel follows”? [This sutta does not apply when a vowel does not follow, such as in] timalaṃ, tiphalaṃ, ticatukkaṃ, tidaṇḍaṃ, tilokaṃ, tinayanaṃ, tipāsaṃ, tihaṃsaṃ, tibhavaṃ, tikhandhaṃ, tipiṭakaṃ, tivedanaṃ, catuddisaṃ, puthubhūtaṃ.

What is the purpose of saying “optionally”? [This sutta does not apply in] pañcah’ aṅgehi, tīhākārehi, cakkh’ āyatanaṃ.

“Vā” is used in the meaning of alternative (vikappana). [By that “vā”] the letter ‘i’ is substituted by ‘aya’. Vatthuttayaṃ = vatthutti + si (by “vā” of this sutta, ‘i’ of ‘ti’ is substituted by ‘aya’; ‘si’ is substituted by ‘aṃ’).