इको गुण-वृद्धी

This is a paribhasha sutra, and is useful in determining the original letters, in the place of which the substitute guna and vriddhi letters will come. The present rule will apply where there is the specification of no other particular rule.

Thus sutra 7.3.84 declares:- \when a sarvadhatuka or an ardhadhatuka affix follows there is guna of the base.\ Here the sthani or the original expression which is to be gunated, is not specified, and to complete the sense, the word \ikah\ must be read into the sutra. The rule then being, \when a S. or an A. affix follows there is guna of the ik vowels of the base.\ The guna of इ or ई is ए; of उ or ऊ, is ओ, of ऋ or ॠ is अर्, of ऌ is अल्; and their Vrddhi is ऐ, औ, आर् and आल् respectively. Thus नी + अति = ने + अति = नयति \he leads.\

Therefore, wherever in any rule in this Grammar, guna or vriddhi is ordained by employing the terms guņa or vriddhi, there the word \ikah\ in the genitive case, meaning \in the place of ik\, is to be supplied to complete the sense.

The word 'ik' is thus understood in the following rules, and is there qualified by the term अङ्ग or 'base':- मिदेर्गुणः 7.3.82 मृजेर्वृद्धिः 7.2.114 पुगन्तलघूपध &c., 7.3.86; ऋच्छत्यॄताम् 7.4.11 ऋदृशोऽङि गुणः 7.4.16 स्थूलदूरयुव &c., 6.4.156.

In the following sutras, the term 'ik' is understood and qualifies the word ånga or base, जुसि च 7.3.83, सार्वधातुकार्धधातुकयोः 7.3.84.

These sutras will be explained in their proper places.

The word 'ik' has been used in the sutra to show that the long आ, एच् or the diphthongs and हल् or the consonants, are not to take guna or vriddhi by this rule, as in the following examples यानम् \a carriage\, ग्लायति \he feels aversion\, उम्भिता \confined\.

Here ग्लायति is formed by adding the affix तिप्, third person singular termination, with the class a affix शप्, to the root ग्लै; as ग्लै+शप्+तिप्=ग्लै+अ+ति. At this stage, rule 7.3.84, would require the guna substitution of the vowel of the base before the sarvadhatuka termination अ; the guna substitute of ऐ being ए, there would be ग्ले+अति=ग्लयति. But this is wrong, the letter ऐ, being not included in the pratyâhåra ik, is not affected by rule 7.3.84, and there is no guna substitution in this case. Similarly there is no change in the long आ of यानम्. Thus या+ल्युट् 3.3.115 = यानम् 7.1.1. Here had there been guņa by Rule 7.3.84, the आ of या, would have been changed into अ, and the form would have been यनम् which is wrong. But it is not so, as आ is not an इक् vowel. So also उम्भ्+इता = उम्भिता. Here, there is no guna substitution in the place of the consonant भ्.

The repetition of the words guna and vriddhi in this sútra, (though by अनुवृत्ति or the supplying of a word from the previous sūtra, these words followed from the two preceding sutras) is for the purpose of indicating that, this is a restrictive rule applicable only there, where guņa or vriddhi has been ordained by the employment of the words guna or vriddhi. Therefore, it is not so in the following cases :- द्यौः \sky\, पन्थाः \way\ सः \he,\ इमम् \this\. द्यौः is the nominative singular of the base दिव्. It is formed by rule 7.1.84, which declares that \in the nominative singular the letter औ takes the place of दिव्\. Here the letter औ is no doubt a vriddhi letter, but as this substitution is not enjoined by the enunciation of the term vriddhi, औ does not take the place of the vowel इ of दिव्, but it replaces the final व्. Thus दि+औ+स्=द्यौः.

Similarly rule 7.1.85, declares that of the word पथिन्, आ is the substitute. The आ is a vriddhi letter no doubt, but not being enunciated by the term vriddhi, it takes the place of न् of पथिन् and not of इ. Thus we have पन्थाः, the न being added by 7.1.87.

Similarly सः from तद्, which is formed by 7.2.102 \short अ is the substitute of tyad, &c.,\ Here अ takes the place of द्. Thus we have त, which is changed again into स by 7.2.106.,