Digital Systems: Principles and Design

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Digital Systems

We can remove bar over the entire expression, by complementing each variable under it

and then changing sign if + to a dot and if dot then to a +.

TABLE 4.1 Three step method for introducing complement over whole term in a Boolean expression

Exemplary term Step 1: Step 2: Step 3:

complementation Sign change Complementation over whole term

C

+ D +

E

C +

D

+ E C ×

D

× E

CDE××

(A + B ) +

C

()AB+

+ C

()AB+

× C

()ABC+×

TABLE 4.2 Removal of complete bar over the whole term in a Boolean expression

Exemplary term Step 1: Step 2: Sign Step 3:

Complementation Sign change Remove

CDE×× CD E×× CDE++

C +

D

+

E

ACD++

AC D++ AC D××

A ×

C

×

D

4.7 THE SUM OF THE ...