This rule accounts for epenthetic /y/ inserted between a morpheme ending in /i(:)/ and a morpheme beginning in a vowel at the time when the rule applies. (Many underlying sequences of this type are contracted to a long vowel by VV-Contraction P-49, which precedes the present rule. The present rule applies to forms involving long /i:/ at the end of the initial morpheme, which do not undergo P-49, and presurface //i-V// sequences due to w1-Deletion P-9.)
Examples of P-10 are //yi:-a:muny// → /yi:-ya:muny/ 'common fly' (note that w-Insertion P-7 does not apply because of the long /a:/ , and //-w2angidi=a:yu-// → //-w2angidi=wa:yu-// P-6)→ //-w2angidi=a:yu-// P-9) → /-w2angidi=ya:yu-/ 'to cut up flesh (of rays)'.
| (P-10) | y-Insertion | Ø | → y // i(:)-__V(:) |
We might consider extending P-10 to also insert /w/ after /u(:)/ in a similar environment. However, in the relevant cases, with surface sequences like /u-wV/ we are generally dealing with underlying morpheme-initial /w/ Having P-10 (re-)insert /w/ would make sense only if an intervening rule deleted the underlying //w// One could possibly make a case for just such an analysis, with w1-Deletion P-9 deleting //w1// not only after /a(:)/ and /i(:)/ but also /u(:)/