asti in theory is discussed in the shaastra texts of Vyaakarana Nyaaya and Meemaamsaa for different purposes. 

In Vyakarana , Vakyapadiyam discusses asti as 'implied' (or present in the 'deep structure' ) at several different occasions. 

For example, it mentions it as implied when a single word works as a sentence. 

yac cāpy ekaṃ padaṃ dṛṣṭaṃ caritāstikriyaṃ kva cit /
tad vākyāntaram evāhur na tad anyena yujyate // BVaky_2.270 //

On Sat, May 4, 2024 at 11:17 PM jason.cannon-silber--- via INDOLOGY <indology@list.indology.info> wrote:

Dear members of the Indology listserv,

I have recently been wondering about the nature of the copula in Sanskrit grammar (both in theory and in practice), and specifically whether and how often the form asti is used as a copula in Classical Sanskrit. I am sorry if this subject has been raised before on this list, but from my search of the archives it seems it has not been addressed directly.

Any user of Sanskrit will know that there need be no word meaning "to be" (i.e., no copula) in a sentence expressing that "X is Y" (i.e., a nominal sentence). But from the exchange between Profs. Deshpande and Bronkhorst in the pages of Annals BORI, I gather that at least some vaiyākaraṇas understood there to be a "silent," copulative asti in such nominal sentences as Devadattaḥ pācaka odanasya or even Rāmo gataḥ. (Whether Pāṇini himself was likely to have had such an understanding was there the vivādāspada.)

On the other hand, I have been told by someone whose knowledge of Sanskrit usage I hold in high esteem that authors of classical Sanskrit almost never use asti in this way, and that such usage might even be considered wrong. This same person has suggested to me that (part of) the reason for this may lie in the fact that technical terms derived from the form asti (please bear in mind that I am speaking here only of the form asti, not of forms of the root as- in other tenses, persons, or numbers), such as āstika or astitva, are invariably connected with asti's existential (or perhaps "adessive") meaning. I have noted that Speijer seems aware of no such avoidance, and gives a couple examples of what he understands to be copulative asti from the story literature (Sanskrit Syntax §§2-3).

I would therefore like to know if there is any literature discussing this avoidance (or perhaps even proscription) of using asti as copula. A pre-modern discussion would be especially interesting, but I would also appreciate further secondary resources, or even your own thoughts.

With best wishes,
Jason Cannon-Silber


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BoS, MIT School of Vedic Sciences, Pune, Maharashtra
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