2-26
R
S
T
V
f
0
0
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
1
1
0
0
1
0
0
0
0
1
0
1
1
0
1
1
0
1
0
1
1
1
1
1
0
0
0
0
1
0
0
1
1
1
0
1
0
1
1
0
1
1
1
1
1
0
0
0
1
1
0
1
1
1
1
1
0
1
1
1
1
1
1
f = (R+S) (T+V)
Now let’s determine the output expression for the NOR gate in figure 2-25. First write the outputs of
gates 1, 2, and 3:
Figure 2-25. —Logic gate combinations.
Since all three outputs are applied to gate 4, proceed as you would for any NOR gate. We separate
each input to gate 4 with an OR sign (+) and then place a vinculum over the entire expression. The output
expression of gate 4 is:
