I am trying to understand the function of double (?) nasals in Lycian. Usually an /ñ/ is followed by /n/ and so does /m̃/ which is followed by an /m/. What was the function of this spelling in Lycian? Did they really try to produce both nasals or is it an attempt to render a nasal that has lacked a letter.
Kloekhorst 2008 writes the following:
"the difference between /n/ vs. /nn/ and /m/ vs. /mm/ is only relevant in initial and intervocalic position. In all other cases the ‘geminate’ spellings with -ñn- and -m̃m- are automatic and directly comparable to the geminate spellings of the other consonants (p. 128).
He also provides an extremely useful chart:
If I understand Melchert 1994 correctly, this gemination could be viewed as "continuants spreading across a syllable boundary" (p. 265), e.g.
Arm̃ma- = [arm.ma-] < /arma-/
If such a cluster was in initial position, then an anaptycic vowel was insterted there:
km̃mi- [kəm.mi-] < /kmi-/