Number 21 and 23

Translate the statements in Problems 19-28 into symbols. For each simple statement, indicate the meanings of the symbols you use. 19. Neither smoking nor drinking is good for your health. 20. I will not buy a new house unless all provisions of the sale are clearly understood. 21. To obtain the loan, I must have an income of $85,000 per year. 22. I am obligated to pay the rent because I signed the contract. 23. I cannot go with you because I have a previous engagement