Main Page | See live article | Alphabetical index Two sets A and B are said to be equinumerous if they have the same cardinality, i.e., if there exists a bijection f : A --> B. This is denoted The study of cardinality is often called equinumerosity. Sometimes the terms equipollent or even equivalent are used, though equivalent is a bit overused. More at cardinality. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.