The following program calculates the factorial (the product of an integer and all the integers below it for e.g., factorial four ( 4! ) is equal to 24. What are the pre-conditions that need to be true.

DECLARE Integer factorial, count, number ... DISPLAY "Enter a number: " INPUT number WHILE count <= number IF count == 0 THEN SET factorial = factorial * 1 ELSE SET factorial = factorial * count END IF SET count = count + 1 END WHILE ... DISPLAY "Factorial(", number, "): ", factorial

number is a positive integer

SET factorial = 1

number is a positive real

SET count = 0

SET factorial = 0