Original language of Yoga Suutra

[Dmitri]

> From my, rather naive point of view, traditional interpretation involves
a lot of grammatical violence (ignoring cases, subordination, etc.)

Here is an example of ellipsis:

I.34  pracchardanavidhaara.naabhyaa.m vaa praa.nasya

Here, pracchardanavidhaara.na is in neut.,dual, inst. or dat. or abl.
vaa means that it is an alternative to something and
praa.na is in masc.sing. gen.

There is no noun in nom.  That is the first ellipsis.
There is a second one.  Assuming that praa.na specifies
pracchardanavidhaara.na creates a problem:
praa.na in that case should have been before vaa.

Since vaa is refering to pracchardanavidhaara.na, then praa.na in gen. is
related to some other missing noun in nom.

So, there are at least three ellipsises in this suutra: two nouns
(or noun phrases) and a verb.

Traditional rendering of it as

Optionally, by expulsion and retention of breath  (Raama Prasaada)

resorts to grammatical stretch (if not violence) by making vaa separating
a noun and describing it noun, not to mention that vaa
does not have a meaning "optionally", but means an alternative.

The implied meaning might be expressed with

praa.nasya pracchardanavidhaara.naabhyaa.m vaa

more directly.

Consequent suutras I.35-I.39 make the situation much worse by
listing alternatives with vaa in different cases and sometimes as
nouns, sometimes as adjectives, which creates even more gaps.
I.37 is the least  clear one.

Best regards, Dmitri.