[OP hya hyā tya, functioning as relative and as article, rarely as personal pronoun, is a contamination of pIE demonstrative *so sā tod and relative *ḽos ḽā ḽod; it is a late formation in Iranian dialectal times, which is why the anteconsonantal t is not spirantized; it is not genetically the same as the Vedic demonstrative sya-s syā tyad, with which it is phonetically identical. But the category of the definite article was not well developed in OP, as examples show. OP hyāparam ‘afterward’ is abl. hyād + aparam ‘later’; there is no evidence that -d survived final after a long vowel, which would have prevented crasis. OP patiy is not only prefix, preposition, and postposition, but also adverb, as is shown by the use of hyāparam with and without a preceding patiy (as well as by other examples).]