COURSE: Formal Methods in Software Engineering

Let be a class that implements a simple bank account. This class has a field that represents the balance of the account (balance:Integer) and which has an initial value of 0 , as well as the methods deposit(x:Integer) to add - deposit an integer amount x>0 to the account and withdraw (x:Integer) to withdraw - withdraw an integer amount x>0 from the account. If the account has a negative balance (ie if balance