Ordinal numbers | Set theory | Computability theory

Computable ordinal

In mathematics, specifically computability and set theory, an ordinal is said to be computable or recursive if there is a computable well-ordering of a subset of the natural numbers having the order type . It is easy to check that is computable. The successor of a computable ordinal is computable, and the set of all computable ordinals is closed downwards. The supremum of all computable ordinals is called the Church–Kleene ordinal, the first nonrecursive ordinal, and denoted by . The Church–Kleene ordinal is a limit ordinal. An ordinal is computable if and only if it is smaller than . Since there are only countably many computable relations, there are also only countably many computable ordinals. Thus, is countable. The computable ordinals are exactly the ordinals that have an ordinal notation in Kleene's . (Wikipedia).

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The Meaning of Numbers – Categorical Data (1-2)

Numbers can do many functions. Some numbers stand in for names or create categories (nominal & ordinal). Other numbers quantify amounts and measurements (interval & ratio). We begin with categorical data: nominal and ordinal. You will learn the distinctions between nominal and ordinal data

From playlist WK1 Numbers and Variables - Online Statistics for the Flipped Classroom

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R Programming: Introduction: Factors (R Intro-04)

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From playlist R Programming: Intro

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Math 060 Fall 2017 111317C Orthonormal Bases

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From playlist Course 4: Linear Algebra (Fall 2017)

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When Does Exponentiation Commute? (Part 1)

In this video, I'll show how one can find pairs of numbers that can be commuted under exponentiation. That is, we can find pairs of numbers such that x^y = y^x. We will take this equation, x^y = y^x and parametrize it to find these (x,y) pairs. It turns out that there are infinitely many n

From playlist Math

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Orthogonal and Orthonormal Sets of Vectors

This video defines orthogonal and orthonormal sets of vectors.

From playlist Orthogonal and Orthonormal Sets of Vectors

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Real Numbers

http://mathispower4u.wordpress.com/

From playlist Integers

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Function Comparision - Intro to Algorithms

This video is part of an online course, Intro to Algorithms. Check out the course here: https://www.udacity.com/course/cs215.

From playlist Introduction to Algorithms

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Orthonormal Bases

Orthonormal bases. The Gram-Schmidt Procedure. Schuur's Theorem on upper-triangular matrix with respect to an orthonormal basis. The Riesz Representation Theorem.

From playlist Linear Algebra Done Right

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Rick Sommer - Knuth’s Up-Arrow into the Transfinite & Beyond! - G4G14 Apr 2022

Famous for its world-record status, Graham’s number has captured the imagination of recreational mathematicians ever since being introduced by Martin Gardner in Mathematical Recreations in 1977. Knuth’s up-arrow notation builds on a nifty recursion that is used to define Graham’s number, a

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Ordinals of countable order type beyond infinity

We implement an order of order type beyond the first infinite one, in a straight forward fashion. To that end, we arrange the natural numbers in an order with countably infinitely many jumps. So there are many numbers that come, with respect to our order, after an infinite amount of number

From playlist Programming

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Linear Algebra - Lecture 39 - Orthonormal Sets

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From playlist Linear Algebra Lectures

Related pages

Ordinal analysis | Kleene's O | Well-order | Large countable ordinal | Set theory | Arithmetical hierarchy | Countable set | Order type | Limit ordinal | Mathematics | Set (mathematics) | Closure (mathematics) | Ordinal notation | Computability theory | Computable set | Successor ordinal | Ordinal number | Subset