Alex is a 60 year-old barber who owns Suburban Barbershop, a sole proprietorship, and wants to retire very soon. Alex has an apprentice barber, Phil, who knows exactly how to cut hair like Alex does. Phil wants to buy Alex's business when Alex retires. The barbershop has $10,000 worth of physical assets; yet the business is valued at $60,000. That difference between these two amounts reflects "business goodwill" or the expected patronage of customers. Phil is willing to buy the business for $60,000 but worries that Alex could sabotage the business goodwill by changing his mind about retirement and opening up a competing venture nearby. Phil wants to insert a clause in the contract selling the business that would take care of this problem. As his lawyer, how would you write the clause? And explain exactly why it is that you need to pay special attention to the terms of this particular clause.