| 释义 |
cardinal number The number of elements in a set. If two sets can be put in one-to-one correspondence with one another they have the same cardinal number or cardinality. For finite sets the cardinal numbers are 0, 1, 2, 3,…, but infinite sets require new symbols to describe their cardinality. The cardinal number of the natural numbers, integers, and rational numbers is aleph-null. The cardinal number of the real numbers is denoted c (for continuum).
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