Suitability of A_4 as a Family Symmetry in Grand Unification
  In the recent successful applications of the non-Abelian discrete symmetry A_4 to the tribimaximal mixing of neutrinos, lepton doublets and singlets do not transform in the same way. It appears thus to be unsuitable as a family symmetry in grand unification. A simple resolution of this dilemma is proposed. 
Ernest Ma (UC Riverside)