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
Chronic rhinitis and post-nasal drip definition and facts. 1  Rhinitis is inflammation of the nose. 2  Symptoms of rhinitis include runny nose (rhinorrhea), nasal itching, nasal congestion, and sneezing.  Rhinitis is categorized into allergic rhinitis (hay fever), non-allergic rhinitis, and mixed rhinitis (a combination of allergic and non-allergic).