A set is countable if: (1) it is finite, or (2) it has the same cardinality (size) as the set of natural numbers. Equivalently, a set is countable if it has the same cardinality as some subset of the set of natural numbers.Otherwise, it is uncountable.heorem: The set of all finite subsets of the natural numbers is countable. If you have a finite subset, you can order the elements into a finite sequence. There are only countably many finite sequences, so also there are only countably many finite subsets.
Rhinitis: Introduction. Rhinitis: Nasal lining inflammation leading to runny/blocked nose. More detailed information about the symptoms, causes, and treatments of Rhinitis is available below. Symptoms of Rhinitis
Irritants or allergens (substances that provoke an allergic response) may cause rhinitis. The cells of your body react to these irritants or allergens by releasing histamine and other chemicals. Rhinitis is often a temporary condition. It clears up on its own after a few days for many people.