Need help locating these three question in the IRS publication. Please cite IRS publication # Thank you.

1. If a shareholder holds a stock right past the expiration date, so that it expires and becomes worthless, does the shareholder recognize a deductible loss?
2. If a shareholder sells a stock right, what is the formula for computing his or her basis in the stock right for purposes of determining taxable gain or deductible loss on the sale?
3. If a shareholder exercises a stock right, what is the formula for computing his or her basis in the share of common stock acquired?