Discrete Mathematics/Functions and relations. This article examines the concepts of the function and the relation. A relation is any association or link between elements of one set, called the domain or (less formally) the set of inputs, and another set, called the range or set of outputs.
Sleep deprivation. Sleep deprivation is the condition of not having enough sleep; it can be either chronic or acute. A chronic sleep-restricted state can cause fatigue, daytime sleepiness, clumsiness and weight loss or weight gain. It adversely affects the brain and cognitive function.
10 Things to Hate About Sleep Loss. You know lack of sleep can make you grumpy and foggy. You may not know what it can do to your sex life, memory, health, looks, and even ability to lose weight. Here are 10 surprising -- and serious -- effects of sleep loss. 1. Sleepiness Causes Accidents.