The document discusses logic gates and their properties. It defines logical addition and multiplication operators and their truth tables. The commutative, associative, and distributive laws for logical operators are also described. Finally, it explains the three basic logic gates - OR, AND, and NOT - and their symbols and behaviors.

3. The logical addition (+) symbol is placed between two variables, say
A and B
0 + 0 = 0
0 + 1 =1
1 + 0 = 1
1 + 1 = 1
The plus symbol (+) read as "OR", therefore A +B is read as A OR B
The logical addition (.) symbol is placed between two variables, say A
and B
0 . 0 = 0
0 . 1 =0
1 . 0 = 0
1 . 1 = 1
The plus symbol (.) read as “AND", therefore A .B is read as AAND B

4. The commutative law for addition and multiplication of two variables
is written as,
A + B = B + A
& A . B = B . A
The associative law for addition and multiplication of three variables
is written as,
(A + B) + C = A + (B + C)
& (A .B) . C = A. (B. C)
The distributive law for three variables involves, both addition
& multiplication and is written as,
A (B+ C) = A B + AC

5. A logic gate is defined as a electronics circuit with two or more input
signals and one output signal. These gates are classified into two
types
• Basic Gates
• Derived Gates
There are three basic gates. They are
• OR gate
• AND gate
• NOT gate

6. It is a basic gate which will have multiple inputs and one output. It is
represented by the symbol ‘+’

7. Output of the OR gate will be high when any one of the input is high

8. It is a basic gate which will have multiple inputs and one output. It is
represented by the symbol ‘.’

9. Output of the AND gate will be high when all the inputs are high

10. It is a basic gate which will have one input and one output. It is
represented by ‘_’
Output of the NOT gate will be complement of input

12. • The positive logic
• The negative logic