Classes: close-mid back rounded vowel
Implicit classes: vocalic V
Features: -high -low +back +round +syllabic +voice
Related rules
Origin
grk-laryngeal-vocalization: h₁e > e, h₂e > a, h₃e > ogrk-cowgills-law: o > u / [nasal]_[labiovelar], o > u / [labiovelar]_[nasal]