1. 4 Computer Circuits
   1. 4.1 Basic Circuits
   2. 4.2 Circuit Models
      1. 4.2.1 OR Model
      2. 4.2.2 Examples:
      3. 4.2.4 AND Model
      4. 4.2.5 Examples:
      5. 4.2.6 NOT Model
      6. 4.2.7 Examples:
   3. 4.3 HALF-ADDER Model
      1. 4.3.1 XOR Model
   4. 4.4 1 Bit Binary Adder
      1. 4.4.1 BIT-ADDER Model
      2. 4.4.2 BIT-ADDER Symbol
   5. 4.5 2-BIT-ADDER
      1. 4.5.1 Wire Model
      2. 4.5.2 2-BIT-ADDER Model
      3. 4.5.3 Examples:
      4. 4.5.4 Exercise
   6. 4.6 4-BIT-ADDER
      1. 4.6.1 4-BIT-ADDER MODEL
      2. 4.6.2 Examples:
      3. 4.6.3 Exercise
      4. 4.6.4 Exercise
   7. 4.7 Complement Arithmetic
   8. 4.8 Modeling Subtraction
   9. 4.9 4-BIT-ALU
      1. 4.9.1 4-BIT-ALU Model
      2. 4.9.2 Examples:
   10. 4.10 Processor Model