680
Boolean Algebra and Computer Logic
17. Use a Karnaugh map to find
a minimal sum-of-products
expression for the network of
three variables shown in the
figure. Sketch the new network.
18. At Rats R Us, you found a standard sum-of-products form for the logic to control valves A and B
( Exercise 39, Section 8.2). Now earn yourself a raise by using Karnaugh maps to minimize these
expressions.
19. Use a Karnaugh map to find a minimal sum-of-products form for the truth function in the table. Don’tcare conditions are shown by dashes.
x 1
x 2
x 3
x 4
f( x 1 , x 2 , x 3 , x 4 )
1
1
1
1
0
1
1
1
0
1
1
1
0
1
0
1
1
0
0
–
1
0
1
1
0
1
0
1
0
–
1
0
0
1
0
1
0
0
0
0
0
1
1
1
0
0
1
1
0
1
0
1
0
1
0
0
1
0
0
1
0
0
1
1
1
0
0
1
0
0
0
0
0
1
–
0
0
0
0
0
x 1
x 2
x 3
x 1
x 2
x 3
x 1
x 2
x 3
x 1
x 2
x 3
x 1
x 2
x 3