Find the complement of the following expression:
X' + XY'

State the two absorption laws. Verify any one of them using truth table.

Reduce the following Boolean expression into their simplest forms:

1. {(CD)' + A} + A + C.D + A.B
2. A.{B + C (A.B + A.C)'}

Give the dual of the following:
(A' B) + (C' 1) = (A' + C) (B + C)