Ilk. double spirants became single; [{xθ}θ|xx] > [θ|x]

Ilk. double spirants became single; [{xθ}θ|xx] > [θ|x]

It appears that in Ilkorin, double spirants reduced to single spirants. The clearest example of this is ᴹ✶b’rittē > [briθθe >] Ilk. brith [briθ] (Ety/BIRÍT). Another possible example is ᴹ√TAK > [takka > taxxa >] Ilk. tâch [tāx] (Ety/TAK) as suggested by Helge Fauskanger (AL-Ilkorin/tâch). In the case of primitive [kt] or [ktʰ], it seems the development was to [xθ] and then [θ], for example: ᴹ✶oktā > [oxθa >] Ilk. oth (Ety/OKTĀ). There are no examples of the development for other spirant pairs, but perhaps the preceding spirant assimilated to the following one as a general rule. If so, the assimilation could also have occurred earlier, when the sounds were still stops (as suggested by Helge Fausganger, AL-Ilkorin/oth).

Phonetic Rule Elements

[θθ] > [θ]
[xθ] > [θ]
[xx] > [x]

Phonetic Rule Examples

taxxa > taxa xx > x ᴹ√TAK > Ilk. tāch ✧ Ety/TAK
luxθe > luθe xθ > θ ᴹ√LUK > Dor. luth ✧ Ety/LUK
luxθiēne > luθiēne xθ > θ ᴹ✶luktı̯ēnē > Dor. Luthien ✧ Ety/LUK
oxθa > oθa xθ > θ ᴹ✶OKTĀ > Ilk. oth ✧ Ety/OKTĀ
-aθθa > -aθ θθ > θ ᴹ✶-atta > Ilk. -ath ✧ PE21/57
bereθθe > bereθe θθ > θ ᴹ√BER > Ilk. bereth ✧ Ety/BER
bríθθe > bríθe θθ > θ ᴹ✶b’rittē > Ilk. brith ✧ Ety/BIRÍT
mboθθo > mboθo θθ > θ ᴹ√MBOTH > Dor. moth ✧ Ety/MBOTH