A = A U '('A U B)
I know how to prove A U '('A U B) but how do I prove the other side? Is this correct? Is it ok just to add 'B?
A /* identity laws */
A U Ø /*domination laws */
A U (Ø ∩ 'B) /* distributive laws */
(A U Ø) ∩ ( A U 'B) /*identity laws */
A ∩ ( A U 'B) /* distributive laws */
(A ∩ A) U (A ∩ 'B) /*idempotent laws */
A U (A ∩ 'B) /*de morgan's laws */
A U '('A U B)