20.

(Continued)

The AND-logic symbol may have two or more inputs; however, to accommodate more

than three inputs, the input side of the symbol is extended, as shown by the diagram on the

conditions are true. The logic diagram and the truth table for a three-input AND operation

are shown below. Note that the output is true (1) only when all inputs are true (1).

Construct a truth table for the two-input AND operation below.

The NOT function is indicated by

21.

a. the absence of 0's and 1's.

b. a vinculum over the variable.

c. the mathematical addition symbol (+).

d. the mathematical multiplication symbol (x).