Explain briefly whether and to what extent the following are allowable deductions: 

(f) Interest on loan to buy computer. The taxpayer uses the computer to do work at home. Her employer provides her with a computer to use at work but she does additional work at home. 

(g) An accountant's annual subscription to the Institute of Chartered Accountants of $600. 

{h) Cost of overseas calls by an employee on his home telephone to discuss sales results with his boss.