# Logic Structures & Mathematical Reasoning

## Application of Logic

### NOT-Gate

A NOT-gate (or inverter) is a circuit with one input and one output signal. If the input signal is 1, the output signal is 0. Conversely, if the input signal is 0, then the output signal is 1.

### AND-Gate

An AND-gate is a circuit with two input signals and one output signal. If both input signals are 1, the output signal is 1. Otherwise the output signal is 0. Symbolic representation & Input/Output Table is shown below.

### OR-Gate

An OR-gate is a circuit with two input signals and one output signal. If both input signals are 0, then the output signal is 0. Otherwise, the output signal is 1. Symbolic representation & Input/Output Table is shown below.

### Combinatorial Circuit:

A Combinational Circuit is a compound circuit consisting of the basic logic gates such as NOT, AND, OR.

### Exercise and Solution

Determine the output for a given input:
Indicate the output of the circuit below when the input signals are P = 1, Q = 0 and R = 0. See the diagram below:

Solution: