अच्सन्धिप्रकरणम्

Covers SK 47–89 (43 sūtras): all present.

ac-sandhi-prakaraṇa — outline (p03, SK 47–89, all 43 sūtras)

Vowel-junction (ac-sandhi): what to do when a word ending in a vowel meets a word/affix beginning with a vowel. Seven outcome-groups, kept close to SK order. Ordering note: 74 upasargādṛti and 77 vā supyāpiśaleḥ are placed with the vṛddhi group D (they produce vṛddhi), though they arise as guṇa-complications; where guṇa is the default (C) but is overridden, the overriding rule sits in D (vṛddhi) or E (pararūpa).

A. yaṇ-sandhi and the doubling / sthānivadbhāva apparatus it triggers — running example: sudhī + upāsyaḥ → suddhy upāsyaḥ

• 47 iko yaṇaci 6.1.77 — an ik (i u ṛ ḷ) → its matching yaṇ (y v r l) when an ac follows. The ī of sudhī is the ik; the u of upāsyaḥ is the ac after it; ī → y (nearest, tālu-place): sudhy upāsyaḥ.
• 48 anaci ca 8.4.47 — a yar consonant after an ac optionally doubles when a non-ac (or nothing) follows. The dh of sudhy, after vowel u, before y → dh may double: suddhy upāsyaḥ (optional).
• 49 sthānivadādeśo'nalvidhau 1.1.56 — a substitute is treated like its sthānin, except in an al-vidhi (a rule keyed to the substitute's own phonetic form). Blocks the worry that y (= ī = an ac) would forbid the doubling of 48: doubling is an al-vidhi, so sthānivadbhāva is off there.
• 50 acaḥ parasmin pūrvavidhau 1.1.57 — an ac-substitute conditioned by what follows is sthānivat for a rule that refers to the preceding element. General enabling paribhāṣā; leads toward 51.
• 51 na padāntadvirvacana… 1.1.58 — switches sthānivadbhāva OFF for ten operations — padānta, dvirvacana (doubling), vare, ya-lopa, svara, savarṇa, anusvāra, dīrgha, jaścar. That the y is not sthānivat for doubling is what licenses 48 on suddhy.
• 52 jhalāṃ jaś jhaśi 8.4.53 — a jhal → its jaś before a jhaś. In the doubled cluster dh-dh, the first dh → d: suddhy upāsyaḥ, the running form realized.
• 53 adarśanaṃ lopaḥ 1.1.60 — saṃjñā: the non-appearance of something that was due is named lopa (used by 54's ya-drop, 60, 67, 71).
• 54 saṃyogāntasya lopaḥ 8.2.23 — a pada ending in a consonant-cluster drops its final consonant → threatens to drop the y of sudhy. Two vārttikas: yaṇaḥ pratiṣedho vācyaḥ (prohibit this ya-lopa for yaṇ) and yaṇo mayo dve (yaṇ before a may double); dh-doubling (48) × y-doubling together yield four forms — suddhy upāsyaḥ, maddhvariḥ, dhātraṃśaḥ, lākṛtiḥ.
• 55 nādinyākrośe putrasya 8.4.48 — no doubling of putra before ādinī in an insult: putrādinī tvam asi (but non-insult puttrādinī). Vārttikas: tatpare ca (putraputtrādinī), vā hatajagdhayoḥ (optional: putrahatī/puttrahatī).
• 56 triprabhṛtiṣu śākaṭāyanasya 8.4.50 — per Śākaṭāyana, when three-plus consonants conjoin, doubling is optional: inndraḥ/indraḥ, rāṣṣṭram/rāṣṭram.
• 57 sarvatra śākalyasya 8.4.51 — per Śākalya, no doubling at all: arkaḥ, brahmā.
• 58 dīrghādācāryāṇām 8.4.52 — per the ācāryas, no doubling after a long vowel: dātram, pātram.
• 59 aco rahābhyāṃ dve 8.4.46 — a yar after r or h (itself after an ac) optionally doubles: haryyanubhavaḥ, nahyyasti.
• 60 halo yamāṃ yami lopaḥ 8.4.64 — a yam after a hal optionally drops before a homogeneous yam; its single-form output matches the no-doubling option, its point being lopa in ādityam (from ādi-tya). yathāsaṃkhya limits it (yam↔yam), so not in māhātmyam.

B. ay / av-sandhi — the ec → ay av āy āv substitutes — running example: hare + e → haraye (also viṣṇo + e → viṣṇave)

• 61 eco'yavāyāvaḥ 6.1.78 — an ec (e o ai au) → ay av āy āv respectively (by yathāsaṃkhya) before an ac. The e of hare, before the dative e, → ay: haray + e.
• 62 tasya lopaḥ 1.3.9 — an it drops; but the y/v of ay/av are not its (they have uccāraṇa-sāmarthya, needed for pronunciation), so no lopa and no it-status: haraye, viṣṇave, nāyakaḥ, pāvakaḥ.
• 63 vānto yi pratyaye 6.1.79 — o/au → av/āv (a v-ending, "vānta") before a ya-affix: go+ya → gavyam, nau+ya → nāvyam. Vārttikas gor yūtau / adhvaparimāṇe ca → gavyūtiḥ.
• 64 dhātostannimittasyaiva 6.1.80 — that vānta substitute (63) applies only to a dhātu's ec conditioned by that very ya-affix: lavyam, avaśyalāvyam; not oyate, auyata (ec not affix-caused).
• 65 kṣayyajayyau śakyārthe 6.1.81 — nipātana fixing a yānta (y-ending) form in the "capable-of" sense: kṣayyam (fit-to-be-decayed), jayyam; contrast the "worthy-of" sense kṣeyam, jeyam.
• 66 krayyastadarthe 6.1.82 — nipātana: krayyam = goods spread for sale (for the buyers' sake); otherwise kreyam (worth buying).
• 67 lopaḥ śākalyasya 8.3.19 — per Śākalya, a pada-final y/v (from ay/av) after an a-varṇa optionally drops before a consonant (aś): hara ehi/harayehi, viṣṇa iha/viṣṇaviha, śriyā udyataḥ/śriyāyudyataḥ. By pūrvatrāsiddha (8.2.1) the lopa-rule is asiddha, so no further vowel-sandhi on the exposed vowels.

C. guṇa ekādeśa — a-varṇa + ac → one guṇa vowel — running example: upa + indraḥ → upendraḥ (also gaṅgā + udakam → gaṅgodakam, kṛṣṇa + ṛddhi → kṛṣṇarddhi)

• 68 ekaḥ pūrvaparayoḥ 6.1.84 — adhikāra: a single substitute stands in place of BOTH the preceding and the following vowel. Governs 69–89.
• 69 ādguṇaḥ 6.1.87 — after an a-varṇa, when an ac follows, one guṇa replaces both, in saṃhitā: upa+i → e (upendraḥ), ramā+ī → e (rameśaḥ), gaṅgā+u → o (gaṅgodakam), each guṇa chosen by nearest place.
• 70 uraṇ raparaḥ 1.1.51 — where the substitute for ṛ-varṇa (or ḷ) is an aṇ, it comes r-para (with a following r/l). kṛṣṇa+ṛddhi: guṇa a → ar (kṛṣṇarddhi); tava+ḷkāra: a → al (tavalkāra).
• 71 jharo jhari savarṇe 8.4.65 — a jhar after a hal optionally drops before a homogeneous jhar → cleanup on the ddh cluster of kṛṣṇarddhi: three forms kṛṣṇardhi / kṛṣṇarddhi / kṛṣṇardddhi. With the yaṇo-mayo-dve option, l doubles in tavalkāra → the traditional four forms.

D. vṛddhi ekādeśa — a-varṇa + ec (and the ṛ-dhātu cases) → one vṛddhi vowel — running example: kṛṣṇa + ekatvam → kṛṣṇaikatvam (also upa + eti → upaiti, upa + ṛcchati → upārcchati)

• 72 vṛddhir eci 6.1.88 — after a-varṇa, when an ec follows, one vṛddhi replaces both (apavāda to guṇa/69): kṛṣṇa+e → ai (kṛṣṇaikatvam), gaṅgā+o → au (gaṅgaughaḥ), deva+ai → ai (devaiśvaryam), kṛṣṇa+au → au (kṛṣṇautkaṇṭhyam).
• 73 etyedhatyūṭhsu 6.1.89 — after a-varṇa, vṛddhi before the ej-initial eti / edhati and before ūṭh (apavāda to pararūpa/78 and guṇa): upaiti, upaidhate, praṣṭhauhaḥ; not upetaḥ, not preidhat. Rich vārttika set: akṣāhini (akṣauhiṇī), svādīreriṇoḥ (svairī/svairiṇī), prādūhoḍha… (prauhḥ, prauḍhaḥ, praiṣaḥ, praiṣyaḥ), ṛte ca tṛtīyāsamāse (sukhārtaḥ), pravatsatara…ṛṇe (prārṇam, daśārṇaḥ).
• 74 upasargādṛti dhātau 6.1.91 — after an a-varṇa upasarga, vṛddhi before an ṛ-initial dhātu: upa+ṛcchati → upārcchati, pra+ṛcchati → prārcchati (overrides the ād-guṇa that a+ṛ would give).
• 75 antādivacca 6.1.85 — that single ekādeśa is antavat (final of the preceding pada) and ādivat (initial of the following) → the r of uraṇ-raparaḥ (in kṛṣṇar-, prārcch-) counts as pada-final for downstream rules.
• 76 kharavasānayor visarjanīyaḥ 8.3.15 — a pada-final r → visarga before a khar or at pause; but here antavadbhāva (75) blocks it, so no visarga on that internal r. Its second service: the yoga-vibhāga isolating "dhātau" re-authorizes the vṛddhi of 74/77 and denies the optional prakṛti-bhāva of ṛtyakaḥ (SK 92) here.
• 77 vā supyāpiśaleḥ 6.1.92 — like 74 but before an ṛ-initial subanta dhātu, vṛddhi is optional (Āpiśali named as honor): pra+ṛṣabhīyati → prārṣabhīyati/prarṣabhīyati; ḷ taken too by sāvarṇya (prālkārīyati); ta-para blocks lengthening (upaṛkārīyati/uparkārīyati).

E. pararūpa (and the ṭi saṃjñā that scopes it) — a + eṅ → the following form — running example: pra + ejate → prejate (also upa + oṣati → upoṣati)

• 78 eṅi pararūpam 6.1.94 — after an a-varṇa upasarga, when an eṅ-initial dhātu follows, the single substitute is the para-rūpa (the following vowel's form): pra+ejate → prejate, upa+oṣati → upoṣati. By vākya-bheda extends to eṅ-initial subanta dhātus (upeḍakīyati/upaiḍakīyati, proghīyati/praughīyati). Vārttika eve cāniyoge (kveva).
• 79 aco'ntyādi ṭi 1.1.64 — saṃjñā: in a run of vowels, the last one together with what follows is ṭi; the pararūpa replaces only that ṭi. Vārttikas: śakandhvādiṣu pararūpaṃ (of the ṭi): śakandhuḥ, karkandhuḥ, kulaṭā, sīmantaḥ (parting of hair), manīṣā, mārtaṇḍaḥ; ottvoṣṭhayoḥ samāse vā (sthūlotuḥ/sthūlautuḥ, bimboṣṭhaḥ/bimbauṣṭhaḥ).
• 80 omāṅośca 6.1.95 — after a, before om or the particle āṅ, pararūpa: śivāya+om → śivāyoṃ namaḥ; śiva+ā(ehi) → śivehi.
• 81 avyaktānukaraṇasyāta itau 6.1.98 — an inarticulate-sound imitation ending in a, before iti, gives pararūpa: paṭat+iti → paṭiti. Vārttika ekāco na (a monosyllabic imitation excepted: śrad iti).
• 82 nāmreḍitasyāntyasya tu vā 6.1.99 — the foregoing (81) does not apply to an āmreḍita (the doubled member); only its final t optionally undergoes it. Vārttika: ḍāc-doubling (bahula) authorizes the doubling itself.
• 83 tasya paramāmreḍitam 8.1.2 — saṃjñā: in a doubling, the second member is the āmreḍita: paṭat-paṭā.
• 84 jhalāṃ jaśo'nte 8.2.39 — a pada-final jhal → its jaś: the final t of the first paṭat → d before the āmreḍita → paṭatpaṭat becomes paṭadpaṭat… (the running āmreḍita form paṭatpaṭā/paṭatpaṭat shows the jaścar).

F. savarṇa-dīrgha — ak + homogeneous ac → one long vowel — running example: daitya + ariḥ → daityāriḥ (also śrī + īśaḥ → śrīśaḥ, viṣṇu + udayaḥ → viṣṇūdayaḥ)

• 85 akaḥ savarṇe dīrghaḥ 6.1.101 — an ak (a i u ṛ ḷ) before a homogeneous ac → one long vowel: a+a → ā (daityāriḥ), ī+ī → ī (śrīśaḥ), u+u → ū (viṣṇūdayaḥ); not before a non-homogeneous vowel (kumārī śete). Vārttikas: ṛti savarṇe ṛ vā (hotṛkāraḥ/hotṝkāraḥ), ḷti savarṇe ḷ vā (hotḷkāraḥ/hotṝkāraḥ).

G. pūrvarūpa and the go-cases at pada-end — running example: hare + ava → hare'va; then the go-set go + agram, go + indraḥ

• 86 eṅaḥ padāntādati 6.1.109 — a pada-final eṅ (e/o), when short a follows, → pūrva-rūpa (keeps the preceding form): hare+ava → hare'va, viṣṇo+ava → viṣṇo'va (overriding the ay/av of 61).
• 87 sarvatra vibhāṣā goḥ 6.1.122 — everywhere (loka and Veda), the eṅ-final go at pada-end optionally keeps its natural form (prakṛti-bhāva) before a: go+agram → go agram / go'gram. Why eṅ-final? not citragv-agram (o already → v). Why pada-end? not goḥ.
• 88 avaṅ sphoṭāyanasya 6.1.123 — ("ati" now dropped) the o of go at pada-end, before any ac, optionally → avaṅ (Sphoṭāyana, hence optional): go+agram → gav-agram → (savarṇa-dīrgha) gavāgram. Why pada-end? not gavi (o not pada-final → plain av). By vyavasthita-vibhāṣā, obligatory in gavākṣaḥ.
• 89 indre ca 6.1.124 — before indra, go's o → avaṅ obligatorily (removes 88's option): go+indra → gav+indra → (ād-guṇa) gavendraḥ.