出典:Wiktionary
出典:『Wiktionary』 (2025/11/27 23:24 UTC 版)
出典:『Wiktionary』 (2016/04/11 22:34 UTC 版)
出典:Wikipedia
出典:『Wikipedia』 (2011/06/12 18:49 UTC 版)
In mathematics, cardinal numbers, or cardinals for short, are a generalization of the natural numbers used to measure the cardinality (size) of sets. The cardinality of a finite set is a natural number – the number of elements in the set. The transfinite cardinal numbers describe the sizes of infinite sets.
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a cardinal number
a cardinal number
the singular number
奇数.
the plural number