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
Nonallergic rhinitis. Overview. Nonallergic rhinitis involves chronic sneezing or a congested, drippy nose with no apparent cause. The symptoms of nonallergic rhinitis are similar to those of hay fever (allergic rhinitis), but none of the usual evidence of an allergic reaction is present. Nonallergic rhinitis can affect children and adults, but is more common after age 20.