Otherwise, you'll save more tax dollars by foregoing the home mortgage interest deduction and claiming the standard deduction instead. Complete Schedule A and compare the total of your itemized deductions to your standard deduction to find out which method is most advantageous for you.
How long a patent lasts depends on the type of patent being issued and the country issuing the patent. For example, under recent changes in the laws, in the United States, patents are now granted for a term of 20 years from the date of application (14 years for design patents).
For any work created from 1978 to date a copyright is good for the author's life, plus 50 years, with a few exceptions such as work for hire which is owned by the one commissioning the work for a period of 75 years from publication. After that it falls into the public domain.