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
More information about causes of Rhinitis: 1  Medications, drugs, or substances causing Rhinitis (7 listings) 2  Underlying causes of Rhinitis. 3  Rhinitis as a complication caused by other conditions. 4  Rhinitis as a symptom. 5  Medical news summaries relating to Causes of Rhinitis.