1. Prove or disprove each claim below: (a) If AU B is decidable, then A and B are recognizable (5) (b) If An B is recognizable, then A or B is decidable [5] 1. Prove or disprove each claim below: (a) If AU B is decidable, then A and B are recognizable (5) (b) If An B is recognizable, then A or B is decidable [5]