According to many twelvers Prophet PBUh never had daughters other than Fatima, also according to twelvers anyone called abu bakar or Umar or uthman is "denied", meaning that they deny his existence but guess what Their brothers the Zaidi Shiites actually expose their lies because in their texts Ali had a third and youngest son called Omar and that is common knowledge for them, in fact Twelver scholar use the most ridiculous excuses to prove that the Imams never named thier sons names such as "Uthman, Omar, Abu Bakr". But before i tell you anything more, first answer my fundamental question above. Is the Imamah from usool el Din according to the twelvers?