1. Design a combinational logic circuit which will add two 4-bit binary numbers.
2. Minimize the expression described in the truth table of Figure P12.50, and draw the circuit.
Determination of the acceptability of emergency blood transfusions. It is known that human blood can be categorized into four types: A, B, AB, and O. Persons with type A blood can donate to both A and AB types and can receive blood from both A and O types.
Persons with type B blood can donate to both B and AB and can receive from both B and O types. Persons with type AB blood can donate only to type AB, but can receive from any type. Persons with type O blood can donate to any type, but can receive only from type
O. Make appropriate variable assignments, and design a circuit that will approve or disapprove any particular transfusion based on these conditions.