Large countable ordinal — In the mathematical discipline of set theory, there are many ways of describing specific countable ordinals. The smallest ones can be usefully and non circularly expressed in terms of their Cantor normal forms. Beyond that, many ordinals of… … Wikipedia
Veblen ordinal — In mathematics, the Veblen ordinal is either of two large countable ordinals: *The small Veblen ordinal *The large Veblen ordinal … Wikipedia
Small Veblen ordinal — In mathematics, the small Veblen ordinal is a certain large countable ordinal, named after Oswald Veblen. It is occasionally called the Ackermann ordinal, though the Ackermann ordinal described by harvtxt|Ackermann|1951 is somewhat smaller than… … Wikipedia
Ordinal collapsing function — In mathematical logic and set theory, an ordinal collapsing function (or projection function) is a technique for defining (notations for) certain recursive large countable ordinals, whose principle is to give names to certain ordinals much larger … Wikipedia
Ordinal number — This article is about the mathematical concept. For number words denoting a position in a sequence ( first , second , third , etc.), see Ordinal number (linguistics). Representation of the ordinal numbers up to ωω. Each turn of the spiral… … Wikipedia
Ordinal notation — In mathematical logic and set theory, an ordinal notation is a finite sequence of symbols from a finite alphabet which names an ordinal number according to some scheme which gives meaning to the language. There are many such schemes of ordinal… … Wikipedia
Church–Kleene ordinal — In mathematics, the Church–Kleene ordinal, , is a large countable ordinal. It is the smallest non recursive ordinal. It is named after Alonzo Church and S. C. Kleene. References Church, Alonzo; Kleene, S. C. (1937), Formal definitions in the… … Wikipedia
Ackermann ordinal — In mathematics, the Ackermann ordinal is a certain large countable ordinal, named after Wilhelm Ackermann. The term Ackermann ordinal is also occasionally used for the small Veblen ordinal, a somewhat larger ordinal. Unfortunately there is no… … Wikipedia
Bachmann–Howard ordinal — In mathematics, the Bachmann–Howard ordinal (or Howard ordinal) is a large countable ordinal.It is the proof theoretic ordinal of several mathematical theories, such as Kripke–Platek set theory (with the axiom of infinity) and the system CZF of… … Wikipedia
Feferman–Schütte ordinal — In mathematics, the Feferman–Schütte ordinal Gamma;0 is a large countable ordinal.It is the proof theoretic ordinal of several mathematical theories.It is named after Solomon Feferman and Kurt Schütte.It is sometimes said to be the first… … Wikipedia
