Limit Cardinal - Relationship With Ordinal Subscripts

Relationship With Ordinal Subscripts

If the axiom of choice holds, every cardinal number has an initial ordinal. If that initial ordinal is then the cardinal number is of the form for the same ordinal subscript λ. The ordinal λ determines whether is a weak limit cardinal. Because if λ is a successor ordinal then is not a weak limit. Conversely, if a cardinal κ is a successor cardinal, say then Thus, in general, is a weak limit cardinal if and only if λ is zero or a limit ordinal.

Although the ordinal subscript tells whether a cardinal is a weak limit, it does not tell whether a cardinal is a strong limit. For example, ZFC proves that is a weak limit cardinal, but neither proves nor disproves that is a strong limit cardinal (Hrbacek and Jech 1999:168). The generalized continuum hypothesis states that for every infinite cardinal κ. Under this hypothesis, the notions of weak and strong limit cardinals coincide.

Read more about this topic:  Limit Cardinal

Famous quotes containing the words relationship with and/or relationship:

    Guilty, guilty, guilty is the chant divorced parents repeat in their heads. This constant reminder remains just below our consciousness. Nevertheless, its presence clouds our judgment, inhibits our actions, and interferes in our relationship with our children. Guilt is a major roadblock to building a new life for yourself and to being an effective parent.
    Stephanie Marston (20th century)

    It would be a fallacy to deduce that the slow writer necessarily comes up with superior work. There seems to be scant relationship between prolificness and quality.
    Fannie Hurst (1889–1968)