Diagonal intersection

From Wikipedia, the free encyclopedia

Diagonal intersection is a term used in mathematics

If

\langle S_i\rangle_{i<\alpha}

is a sequence then the diagonal intersection,

Δi < αSi

is defined to be

\{\beta<\alpha\mid\beta\in \bigcap_{\gamma<\beta} S_\gamma\}.

That is, β is in Δi < αSi if it is contained in the first β members of the sequence.

[edit] See also

This article incorporates material from diagonal intersection on PlanetMath, which is licensed under the GFDL.

 This mathematical logic-related article is a stub. You can help Wikipedia by expanding it.