Prove or disprove the following expression. (Prove: using Boolean algebra. Disprove: using table) (NOT is presented by -.) a +b(c bar + d) bar = a bar b bar + a bar c d bar ab bar + bc bar + ac bar = (a + b + c) (a bar + b bar + c bar) a bar + bd bar bar(c + d) + ab bar d = ac bar d + ab bar cd +abd