Try to provide a formal proof, and indicate where the proof becomes invalid: [(Vi a(i))+(Vj B(i))] Wk ( [B(k)=v(k)][a(k)=(k)]] Try to provide a formal proof, and indicate where the proof becomes invalid: [(Vi a(i))+(Vj B(i))] Wk ( [B(k)=v(k)][a(k)=(k)]]