Definition: lit. extension; the process of changing a semi-vowel into a simple vowel of the same sthana or place of utterance; the substitution of the vowels इ, उ, ऋ and लृ for the semi-vowels य्, व्, र् and ल् respectively; cf इग्यणः संप्रसारणम् P. 1.1.45. The term संप्रसारण is rendered as a 'resultant vowel' or as 'an emergent vowel'. The ancient term was प्रसारण and possibly it referred to the extension of य् and व्， into their constituent parts इ +अ, उ+अ etc. the vowel अ being of a weak grade but becoming strong after the merging of the subseguent vowel into it e.g. cf. सर्वत्र प्रसारणिभ्यो ड: P. III. 2.8 Vart.1. For the words taking this samprasarana change, see P. VI. 1 .13 to .19. According to some grammarians the term संप्रसारण is applied to the substituted vowels while according to others the term refers to the operation of the substitution: cf. M. Bh. on P. I. 1.15. The substitution of the samprasarana vowel is to be given preference in the formation of a word;, cf. संप्रसारणं तदाश्रयं च कार्यं बलवत् Pari. Sek. Pari. 1 19. संप्रसारणबलीयस्त्व the relative superior strength of the samprasarana change in comparison with other operations occurring simultaneotisly. The phrase न वा संप्रसारणबलीयस्त्वात् is often used in the Mahabhasya which is based upon the dictum of the superior strength of the samprasarana substitution, which is announced by the writer of the Varttikas; P. VI. 1.17 Vart, 2., See संप्रसारण.