S. [n] plus [m] became [mm]; [m+m] > [n+m]

Phonetic Rule Elements

[m+m] > [n+m]

N. [n] plus [m] became [mm]; [m+m] > [n+m]

GS/§4.121 @@@

Order (01800)

Before 02200 short final vowels vanished ON. Boronmíro/Borommíro > N. Boromir Ety/BOR
Before 05400 [mm] shortened ON. Boronmíro/Borommíro > N. Boromir Ety/BOR

Phonetic Rule Elements

[m+m] > [n+m]

Phonetic Rule Examples

boronmiro > borommiro m+m > n+m ON. Boronmíro/Borommíro > N. Boromir ✧ Ety/BOR.056