el, the vowel remains short: thus, acikṣipam, acukrudham, atitrasam, apispṛçam.
860. If the root is a heavy syllable (having a long vowel, or a short before two consonants), the vowel of the reduplication is short: and in this case अ a or आ ā, and ऋ ṛ (if it occurs), are reduplicated by अ a.
a. Thus, adidīkṣam, abubhūṣam (not quotable), adadakṣam, adadhāvam, atataṅsam. And, in the cases in which a root should both begin and end with two consonants, both syllables would be necessarily heavy, notwithstanding the short vowel in the former: thus, apapraccham, acaskandam (but no such forms are found in use).
b. A medial ṛ is allowed by the grammarians to retain the strengthening of the causative stem, together with, of course, reduplication by a: thus, acakarṣat, avavartat (beside acīkṛṣat, avīvṛtat); but no such forms have been met with in use.
c. These aorists are not distinguishable in form from the so-called pluperfects (817 ff.).
861. a. In order, however, to bring about the favored relation of heavy reduplication and light radical syllable, a heavy root is sometimes made light: either by shortening its vowel, as in arīradham from √rādh, avīvaçam from √vāç, asīṣadham from √sādh, ajījivam from √jīv, adīdipam (K. and later: BV. has didīpas) from √dīp, abībhiṣam from √bhīṣ, asūsucam from √sūc; or by dropping a penultimate nasal, as in acikradam from √krand, asiṣyadam from √syand.
b. In those cases in which (1047) an aorist is formed directly from a causal stem in āp, the ā is abbreviated to i: thus, atiṣṭhipam etc., ajijñipat (but KSS. ajijñapat), jīhipas, ajījipata (but VS. ajījapata); but from çrap comes açiçrapāma (ÇB.).
862. Examples of this aorist from roots with initial vowel are very rare; the older language has only āmamat (or amamat) from √am, āpipan (ÇB.: BAU. āpipipat) from √āp, and arpipam (augmentless) from the causative stem arp of √ṛ — in which latter the root is excessively abbreviated. The grammarians give other similar formations, as ārcicam from √arc, āubjijam from √ubj, ārjiham from √arh, āicikṣam from √īkṣ, ārdidham from √ṛdh. Compare the similar reduplication in desiderative stems: 1029 b.
863. Of special irregularities may be mentioned:
a. From √dyut is made (V.B.) the stem didyuta, taking its reduplicating vowel from the radical semivowel. From √gup, instead of jūgupa (B.S.), JB. has jugūpa, and some texts (B.S.) have jugupa; and jīhvara (B.) is met with beside the regular jihvara (V.B.). In caccha-