The finite ordered tree problem was researched by Harvey Friedman. Friedman defines an ordered tree as a triple (V,≤,<') where (V,≤) is a finite poset with a least element (root) in which the set of predecessors under ≤ of each vertex is linearly ordered by ≤, and where for each vertex, <' is a strict linear ordering on its immediate successors. He also defines the following:
* Vertex x ≤* y iff x is to the left of y, or if x ≤ y.
* d(v) is the position of v in counting from 1.
* |T[0]| = 1
* |T[1]| = 2
* |T[2]| = 4
* |T[3]| = 14
* |T[4]| > 243
* |T[5]| > 2↑↑2295
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| rdfs:label
| - Friedman's finite ordered tree problem
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| rdfs:comment
| - The finite ordered tree problem was researched by Harvey Friedman. Friedman defines an ordered tree as a triple (V,≤,<') where (V,≤) is a finite poset with a least element (root) in which the set of predecessors under ≤ of each vertex is linearly ordered by ≤, and where for each vertex, <' is a strict linear ordering on its immediate successors. He also defines the following:
* Vertex x ≤* y iff x is to the left of y, or if x ≤ y.
* d(v) is the position of v in counting from 1.
* |T[0]| = 1
* |T[1]| = 2
* |T[2]| = 4
* |T[3]| = 14
* |T[4]| > 243
* |T[5]| > 2↑↑2295
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| dcterms:subject
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| dbkwik:googology/p...iPageUsesTemplate
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| abstract
| - The finite ordered tree problem was researched by Harvey Friedman. Friedman defines an ordered tree as a triple (V,≤,<') where (V,≤) is a finite poset with a least element (root) in which the set of predecessors under ≤ of each vertex is linearly ordered by ≤, and where for each vertex, <' is a strict linear ordering on its immediate successors. He also defines the following:
* Vertex x ≤* y iff x is to the left of y, or if x ≤ y.
* d(v) is the position of v in counting from 1. He then defines T[k] to be the tree of height k such that every vertex v of height ≤k - 1 has exactly d(v) children, and |T[k]| to be number of children. Friedman has proven that |T[k]| has a similar growth rate to that of the Ackermann function. The first few values are as follows:
* |T[0]| = 1
* |T[1]| = 2
* |T[2]| = 4
* |T[3]| = 14
* |T[4]| > 243
* |T[5]| > 2↑↑2295
|