4. Consider a logic function/circuit P(a,b,c,d) that accepts a single BCD (binary coded decimal) digit. This circuit should detect whether it's input is a prime number. Draw the Truth Table for the function P, using a "don't care" symbol (either a d or an X) for all input values outside the acceptable input range (ie, those inputs that don't represent BCD digits) 20 points a) Draw the truth table below. b) Draw the corresponding K-map for this function and derive a minimal SOP formula for the function. Draw the circuit. Don't forget the "don't care" entries. c Now consider adding some logic that will check for invalid inputs and produce a 1 on an output signal V (for "valid"). This will give your circuit two separate outputs-a P output (number is prime) and an V output (input is valid). Draw a separate K-map for this error-checking function only and derive a minimal Boolean formula for it