<?xml version="1.0"?>
<feed xmlns="http://www.w3.org/2005/Atom" xml:lang="en">
	<id>https://wiki.bbchallenge.org/w/index.php?action=history&amp;feed=atom&amp;title=Fast-Growing_Hierarchy_Growth_Bound_Theorem</id>
	<title>Fast-Growing Hierarchy Growth Bound Theorem - Revision history</title>
	<link rel="self" type="application/atom+xml" href="https://wiki.bbchallenge.org/w/index.php?action=history&amp;feed=atom&amp;title=Fast-Growing_Hierarchy_Growth_Bound_Theorem"/>
	<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=Fast-Growing_Hierarchy_Growth_Bound_Theorem&amp;action=history"/>
	<updated>2026-04-30T19:17:35Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
	<generator>MediaWiki 1.43.5</generator>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=Fast-Growing_Hierarchy_Growth_Bound_Theorem&amp;diff=4987&amp;oldid=prev</id>
		<title>LegionMammal978: redirect</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=Fast-Growing_Hierarchy_Growth_Bound_Theorem&amp;diff=4987&amp;oldid=prev"/>
		<updated>2025-11-04T18:31:56Z</updated>

		<summary type="html">&lt;p&gt;redirect&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 18:31, 4 November 2025&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l1&quot;&gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;{{Stub}}&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;#REDIRECT [[&lt;/ins&gt;Fast-Growing Hierarchy&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;#&lt;/ins&gt;Growth Bound Theorem]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;The &#039;&#039;&lt;/del&gt;Fast-Growing Hierarchy Growth Bound Theorem&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&#039;&#039; is an important result in mathematical logic that has significant implications for unprovability results. The theorem highlights a relationship between computable functions that are provably total in first-order Peano Arithmetic (PA) and the fast-growing functions in the [[Fast-Growing Hierarchy|Wainer hierarchy]].&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;The theorem is based on work by several mathematicians. Georg Kreisel laid the groundwork in 1952 by investigating connections between  recursions over well ordered sets and proofs in PA. These results were subsequently extended by many others; the following form is based on the presentation by Buchholz and Wainer.&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;== Statement ==&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Let &amp;lt;math&amp;gt;T&amp;lt;/math&amp;gt; be a Turing machine that computes a function &amp;lt;math&amp;gt;g:\N\to\N&amp;lt;/math&amp;gt;, terminating on every input. Suppose that PA can prove the statement «&amp;lt;math&amp;gt;T&amp;lt;/math&amp;gt; terminates on every input.» Then &amp;lt;math&amp;gt;g&amp;lt;/math&amp;gt; cannot grow too fast: There exist &amp;lt;math&amp;gt;\alpha &amp;lt; \varepsilon_0&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;n_0\in\N&amp;lt;/math&amp;gt; such that &amp;lt;math&amp;gt;g(n) &amp;lt; F_\alpha(n)&amp;lt;/math&amp;gt; for every &amp;lt;math&amp;gt;n\ge n_0&amp;lt;/math&amp;gt;.&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;== References ==&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Wilfried Buchholz and Stan S. Wainer. Provably computable functions and the fast growing hierarchy. In S. G. Simpson, editor, Logic and Combinatorics, volume 65 of Contemporary Mathematics, pages 179–198. AMS, 1987. [https://epub.ub.uni-muenchen.de/3843/1/3843.pdf]&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Category:Computability theory&lt;/del&gt;]]&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;

&lt;!-- diff cache key mediawiki:diff:1.41:old-2967:rev-4987:php=table --&gt;
&lt;/table&gt;</summary>
		<author><name>LegionMammal978</name></author>
	</entry>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=Fast-Growing_Hierarchy_Growth_Bound_Theorem&amp;diff=2967&amp;oldid=prev</id>
		<title>Polygon: Used Template:Stub</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=Fast-Growing_Hierarchy_Growth_Bound_Theorem&amp;diff=2967&amp;oldid=prev"/>
		<updated>2025-08-10T22:34:43Z</updated>

		<summary type="html">&lt;p&gt;Used Template:Stub&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 22:34, 10 August 2025&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l1&quot;&gt;Line 1:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 1:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;{{Stub}}&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The &amp;#039;&amp;#039;Fast-Growing Hierarchy Growth Bound Theorem&amp;#039;&amp;#039; is an important result in mathematical logic that has significant implications for unprovability results. The theorem highlights a relationship between computable functions that are provably total in first-order Peano Arithmetic (PA) and the fast-growing functions in the [[Fast-Growing Hierarchy|Wainer hierarchy]].&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;The &amp;#039;&amp;#039;Fast-Growing Hierarchy Growth Bound Theorem&amp;#039;&amp;#039; is an important result in mathematical logic that has significant implications for unprovability results. The theorem highlights a relationship between computable functions that are provably total in first-order Peano Arithmetic (PA) and the fast-growing functions in the [[Fast-Growing Hierarchy|Wainer hierarchy]].&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l10&quot;&gt;Line 10:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 11:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Wilfried Buchholz and Stan S. Wainer. Provably computable functions and the fast growing hierarchy. In S. G. Simpson, editor, Logic and Combinatorics, volume 65 of Contemporary Mathematics, pages 179–198. AMS, 1987. [https://epub.ub.uni-muenchen.de/3843/1/3843.pdf]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Wilfried Buchholz and Stan S. Wainer. Provably computable functions and the fast growing hierarchy. In S. G. Simpson, editor, Logic and Combinatorics, volume 65 of Contemporary Mathematics, pages 179–198. AMS, 1987. [https://epub.ub.uni-muenchen.de/3843/1/3843.pdf]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[[Category:Stub]]&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Computability theory]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category:Computability theory]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

&lt;!-- diff cache key mediawiki:diff:1.41:old-936:rev-2967:php=table --&gt;
&lt;/table&gt;</summary>
		<author><name>Polygon</name></author>
	</entry>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=Fast-Growing_Hierarchy_Growth_Bound_Theorem&amp;diff=936&amp;oldid=prev</id>
		<title>Bt2901: Created page with &quot;The &#039;&#039;Fast-Growing Hierarchy Growth Bound Theorem&#039;&#039; is an important result in mathematical logic that has significant implications for unprovability results. The theorem highlights a relationship between computable functions that are provably total in first-order Peano Arithmetic (PA) and the fast-growing functions in the Wainer hierarchy.  The theorem is based on work by several mathematicians. Georg Kreisel laid the groundwork in 1952 by inve...&quot;</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=Fast-Growing_Hierarchy_Growth_Bound_Theorem&amp;diff=936&amp;oldid=prev"/>
		<updated>2024-09-14T22:11:56Z</updated>

		<summary type="html">&lt;p&gt;Created page with &amp;quot;The &amp;#039;&amp;#039;Fast-Growing Hierarchy Growth Bound Theorem&amp;#039;&amp;#039; is an important result in mathematical logic that has significant implications for unprovability results. The theorem highlights a relationship between computable functions that are provably total in first-order Peano Arithmetic (PA) and the fast-growing functions in the &lt;a href=&quot;/wiki/Fast-Growing_Hierarchy&quot; title=&quot;Fast-Growing Hierarchy&quot;&gt;Wainer hierarchy&lt;/a&gt;.  The theorem is based on work by several mathematicians. Georg Kreisel laid the groundwork in 1952 by inve...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;The &amp;#039;&amp;#039;Fast-Growing Hierarchy Growth Bound Theorem&amp;#039;&amp;#039; is an important result in mathematical logic that has significant implications for unprovability results. The theorem highlights a relationship between computable functions that are provably total in first-order Peano Arithmetic (PA) and the fast-growing functions in the [[Fast-Growing Hierarchy|Wainer hierarchy]].&lt;br /&gt;
&lt;br /&gt;
The theorem is based on work by several mathematicians. Georg Kreisel laid the groundwork in 1952 by investigating connections between  recursions over well ordered sets and proofs in PA. These results were subsequently extended by many others; the following form is based on the presentation by Buchholz and Wainer.&lt;br /&gt;
&lt;br /&gt;
== Statement ==&lt;br /&gt;
&lt;br /&gt;
Let &amp;lt;math&amp;gt;T&amp;lt;/math&amp;gt; be a Turing machine that computes a function &amp;lt;math&amp;gt;g:\N\to\N&amp;lt;/math&amp;gt;, terminating on every input. Suppose that PA can prove the statement «&amp;lt;math&amp;gt;T&amp;lt;/math&amp;gt; terminates on every input.» Then &amp;lt;math&amp;gt;g&amp;lt;/math&amp;gt; cannot grow too fast: There exist &amp;lt;math&amp;gt;\alpha &amp;lt; \varepsilon_0&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;n_0\in\N&amp;lt;/math&amp;gt; such that &amp;lt;math&amp;gt;g(n) &amp;lt; F_\alpha(n)&amp;lt;/math&amp;gt; for every &amp;lt;math&amp;gt;n\ge n_0&amp;lt;/math&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
== References ==&lt;br /&gt;
Wilfried Buchholz and Stan S. Wainer. Provably computable functions and the fast growing hierarchy. In S. G. Simpson, editor, Logic and Combinatorics, volume 65 of Contemporary Mathematics, pages 179–198. AMS, 1987. [https://epub.ub.uni-muenchen.de/3843/1/3843.pdf]&lt;br /&gt;
&lt;br /&gt;
[[Category:Stub]]&lt;br /&gt;
[[Category:Computability theory]]&lt;/div&gt;</summary>
		<author><name>Bt2901</name></author>
	</entry>
</feed>