a. Some of the authorities include, along with r, also h or l or v, or more than one of them, in this rule.
b. A doubled consonant after r is very common in manuscripts and inscriptions, as also in native text-editions and in the earlier editions prepared by European scholars — in later ones, the duplication is universally omitted.
c. On the other hand, the manuscripts often write a single consonant after r where a double one is etymologically required: thus, kārtikeya, vārtika, for kārttikeya, vārttika.
229. The first consonant of a group — whether interior, or initial after a vowel of a preceding word — is by the grammarians either allowed or required to be doubled.
a. This duplication is allowed by Pāṇini and required by the Prātiçākhyas — in both, with mention of authorities who deny it altogether. For certain exceptions, see the Prātiçākhyas; the meaning of the whole matter is too obscure to justify the giving of details here.
230. Other cases of extension of consonant-groups, required by some of the grammatical authorities, are the following:
a. Between a non-nasal and a nasal mute, the insertion of so-called yamas (twins), or nasal counterparts, is taught by the Prātiçākhyas (and assumed in Pāṇini’s commentary): see APr. i. 99, note.
b. Between h and a following nasal mute the Prātiçākhyas teach the insertion of a nasal sound called a nāsikya: see APr. i. 100, note.
c. Between r and a following nasal consonant the Prātiçākhyas teach the insertion of a svarabhakti or vowel-fragment: see APr. i. 101–2, note.
d. Some authorities assume this insertion only before a spirant; the others regard it as twice as long before a spirant as before any other consonant — namely, a half or a quarter mora before the former, a quarter or an eight before the latter. One (VPr.) admits it after l as well as r. It is variously described as a fragment of the vowel a or of ṛ (or ḷ).
e. The RPr. puts a svarabhakti also between a sonant consonant and a following mute or spirant; and APr. introduces an element called sphoṭana (distinguisher) between a guttural and a preceding mute of another class.
f. For one or two other cases of yet more doubtful value, see the Prātiçākhyas.
231. After a nasal, the former of two non-nasal mutes may be dropped, whether homogeneous only with the nasal, or with both: thus, yun̄dhí for yun̄gdhí, yun̄dhvám for yun̄gdhvám, ān̄tám for ān̄ktám, pan̄tí for pan̄ktí, chintā́m for chinttā́m, bhinthá for bhintthá, indhé for inddhé.
a. The abbreviation, allowed by Pāṇini, is required by APr. (the other Prātiçākhyas take no notice of it). It is the more usual practice of the manuscripts, though the full group is also often written.
