Final answer:
Personal and living expenses are nondeductible in taxation, unless expressly authorized by a provision in the law.
Step-by-step explanation:
The types of expenses that are nondeductible in taxation, unless expressly authorized by a provision in the law, are personal and living expenses. These are expenses that are incurred for personal purposes and are not directly related to the production of income or the operation of a business. Examples of personal and living expenses include rent, groceries, clothing, and entertainment.