स्वरितो वा ऽनुदात्ते पदादौ

Thus सु + उत्थितः = सू꣡त्थितः or सू॑त्थितः; वि॑ + ईक्षते = वीक्ष꣡ते or वीक्ष॑ते; वसुकः + असि = वसुकोऽ॑सि or वसुकोऽ꣡सि ॥ Here the word सु is a Karmapravachaniya by 1.4.94, when it is compounded by प्रादिसमास with the Past Participle, the Avayayibhava compound retains the accent of its first member 6.2.2, and so it is acutely accented on the first, and the rest are anudatta. Thus the udatta उ꣡ of सु is compounded with the anudatta उ॒॒ of उत्थितः which stands at the beginning of a Pada, and so the ekadesa is optionally svarita. In वीक्षते and वसुकोऽसि also the verbs ईक्षते and असि lose all accent by 8.1.28 and so ई and अ become anudatta, which when compounded with वि and वसुका become optionally svarita.

The word स्वरितः is employed in the sutra only for the sake of distinctness, for the sutra may have well stood as वाऽनुदात्ते पदादौ ॥ In this form of the sutra, the udatta of the preceding sutra would become optional when the second member is a word beginning with anudatta. Udatta being optional, in the other alternative, where there will not be udatta, the svarita will be substituted by reason of the nearness in position.

Why do we say \anudatta beginning\? Observe देवदत्तोऽत्र ॥ Here अत्र begins with udatta and not anudatta, and hence no option is allowed.

Why do we say \beginning of a word\? Observe वृक्षैः, वृक्षाः, प्लक्षैः and प्लक्षाः, where anudatta case-endings are not beginnings of words.

According to Bhattoji Dikshita this is a vyavasthita-vibhasha; in this wise. There will necessarily be svarita (1) where a long ई is the single substitute of (इ + इ) or of two short इ, (2) where there is purva-rupa by the application of एङपदान्तात् अति 6.1.109. There will be udatta where a long vowel comes in. Thus in वि + इदम् = वीद॑म् in वी३दं॒॒ ज्योति॒॒र्हृद॑ये, the long ई is substituted for two short इ's. This substitution of a long ई for two short इ's is technically called प्रश्लेष ॥ Where there is Praslesha, the long ई is necessarily svarita. Similarly when there is अभिनिहतसन्धिः i. e. the peculiar sandhi taught in 6.1.109. Thus ते॑ऽवदन्, सोऽय॒॒मागा॑त् ॥ So also where there is क्षैप्रः सन्धिः i.e. the substitution of a semi-vowel in the room of an udatta or svarita vowel, as अन्या॑भि ॥ The above rules about svarita are thus summarised in the Pratisakhyas : इकारयोश्च प्रश्लेषे क्षैप्राभिनिहतेषु च ॥ But where a long ई is substituted as a single substitute for इ + ई (one of the इ's being long), there it must always be acute. As अस्य श्लोको दि॒॒वीयते (Rig. 1. 190. 4). The words दिवि꣡ + ईय॒॒ते॒॒ are compounded into दिवीयते ॥ The word दिवि꣡ Locative singular is finally acute by 6.1.171. ईयते is from the Divadi root इङ् गतौ, and has lost its accent by 8.1.28.,