Questions

[Dr. M. Giridhar]

>   Why?  In a wider sense, are the vedAngas and the upavedas also
> considered to be shruti?  What exactly constitutes shruti?

        This has been already been explained by Kanchi periyava in the web
page cited earlier.  Further, in North India, there were people who were
chaturvedi, i.e., they could recite all the four vedas.

> Sub-commentraies (VyAkhyA, VarthikA, TikA:

>2.  Is not varTikS also a kind of TikA.  I would be grateful if someone
>could explain the different kinds of sub-commetaries like bhAshyA,
>tippanI, churnI etc.  What purpose does each serve?

        AFAIK,

        bhaashya is not a sub-commentary, but it is a main
commentary on a primary scripture like the Bhagavad gita.
Examples are the various bhashyas by Shankara-acharya.
        vivarana is the critical study and explanation of a bhashya.
Example is the vivarana of Shankara, which explains
the vyasa's bhashya of the yoga sutras.
        varttika is the explanation of a composition.
Examples are the varttika Manasollasa of Suresvaracarya on Sri
Shankaracarya's Dakshinamurti stotra; Bhaskara's vartika on the
Shiva suutras.
        Vritti is a brief commentary, usually on aphorisms.
Aniruddha's vritti on Sankhya suutras, Brahmasutravrttih by
paramananda are quite famous.
        Tippani is a less formal commentary and explains the
difficult words and phrases.
        Tika is same as vyaakhyana and is the explanation
of a bhashya (or scripture) in simple language. The various
tikas on anandalaharii and the tika by anandagiri is an example.