In the logic network shown in Figure PA.3, gate 3 fails and produces the logic value 1 at its output F1 regardless of the inputs. Redraw the network, making simplifications

wherever possible, to obtain a new network that is equivalent to the given faulty network and that contains as few gates as possible. Repeat this problem, assuming that the fault is at position F2, which is stuck at a logic value 0.LO1 

*1 2 x2 X3 6 1 4 F2 8 3 0 Fl 7 x4 Figure PA.3 A faulty network.