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
One American study found that the prevalence of non-allergic rhinitis is greater in females and that the incidence of diagnosis increases with age. Greater than 60% of rhinitis patients over the age of 50 suffer from a non-allergic aetiology. The causes of nasal obstruction are: 1  Infective rhinitis: acute rhinitis is often infective in origin. 2  Viral rhinitis is one of the most frequent causes of nasal obstruction. 3  Bacterial rhinitis may begin spontaneously or as a sequel to viral rhinitis. 4  Fungal rhinitis is most often found (but rarely) in immunocompromised patients. 5  Infection by 6  ... Al