laws (theorems) of boolean algebra laws of complementation othe term complement means, to invert or...

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Laws (Theorems) of Boolean algebra Laws of Complementation o The term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose inverters or NOT gates are used. o A complement of a variable is represented by a bar over the letter. For example, the complement of a variable A will be denoted by A www.bookspar.com | Website for Students | VTU NOTES | QUESTION PAPERS 1

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Page 1: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

Laws (Theorems) of Boolean algebra

Laws of Complementationo The term complement means, to invert or to

change 1's to 0's and 0's to 1's, for which purpose inverters or NOT gates are used.

o A complement of a variable is represented by a bar over the letter. For example, the complement of a variable A will be denoted by A

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QUESTION PAPERS 1

Page 2: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

Law 1: = 1

Law 2: = 0

Law 3: If A = 0,

Law 4: If A = 1,

Law 5:

0

1

1A

0A

AA

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QUESTION PAPERS 2

Page 3: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

AND Laws

• Law 6: A.0=0

• Law 7: A.1=A

• Law 8: A.A=A

• Law 9: 0. AA

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QUESTION PAPERS 3

Page 4: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

OR Laws

• Law 10: A +0 = A

• Law 11: A +1 = 1

• Law 12: A +A = A

• Law 13: 1 AA

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QUESTION PAPERS 4

Page 5: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

Commutative Laws

– This states that the order in which the variables are OR’ed and AND’ed will make no difference in the output.

• Law14: A. B = B. A• Law 15 : A + B = B + A

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QUESTION PAPERS 5

Page 6: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

Associative Laws

This law states that the order in which the variables are grouped will not make any difference in the output.

• Law 16: A + (B + C) = (A + B) + C

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QUESTION PAPERS 6

Page 7: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

• Law 17: A.(B.C) = (A.B).C

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QUESTION PAPERS 7

Page 8: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

Distributive LawsThese laws allow the factoring or multiplying out of

expressions.

• Law 18: A .(B +C) = (A .B) + (A .C)• Law 19: A + (B .C) = (A + B) (A + C)

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QUESTION PAPERS 8

Page 9: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

De Morgan's Theorems

• 1.

• 2.

• The complement of any Boolean expression is found by using these two rules.

YXYX

YXYX

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QUESTION PAPERS 9

Page 10: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

Steps for complementation:

• 1. Replace ‘+’ symbols with ‘.’ symbols and ‘.’ symbols with ‘+’ symbols.

• 2. Complement each term.

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QUESTION PAPERS 10

Page 11: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

Proof of De Morgan's Theorems

YXYX

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QUESTION PAPERS 11

Page 12: Laws (Theorems) of Boolean algebra Laws of Complementation oThe term complement means, to invert or to change 1's to 0's and 0's to 1's, for which purpose

YXYX

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QUESTION PAPERS 12