Use decomposition to find minimum gate-input cost, multiple-level implementations for the functions given, using AND and OR gates and inverters.

(a) \(F(A, B, C, D)=A \bar{B} C+\bar{A} B C+A \bar{B} D+\bar{A} B D\)

(b) \(F(W, X, Y, Z)=W Y+X Y+\bar{W} X Z+W \bar{X} Z\)