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	<id>https://wiki.bbchallenge.org/w/index.php?action=history&amp;feed=atom&amp;title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD</id>
	<title>0RB1RZ0RB 1RC1LB2LB 1LB2RD1LC 1RA2RC0LD - 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=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD"/>
	<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;action=history"/>
	<updated>2026-04-30T16:39:22Z</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=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=4695&amp;oldid=prev</id>
		<title>Polygon: as --&gt; in</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=4695&amp;oldid=prev"/>
		<updated>2025-10-23T17:31:54Z</updated>

		<summary type="html">&lt;p&gt;as --&amp;gt; in&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;
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				&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 17:31, 23 October 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-l4&quot;&gt;Line 4:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 4:&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;&amp;lt;math display=&amp;quot;block&amp;quot;&amp;gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1}) \text{ and } 2 \uparrow\uparrow\uparrow (2^{2^{32}+1}+1)&amp;lt;/math&amp;gt;&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;&amp;lt;math display=&amp;quot;block&amp;quot;&amp;gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1}) \text{ and } 2 \uparrow\uparrow\uparrow (2^{2^{32}+1}+1)&amp;lt;/math&amp;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;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;steps. The TM was discovered by Pavel Kropitz in May 2024 &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;as &lt;/del&gt;a group of 7 long-running halting BB(4,3) TMs.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&amp;lt;/ref&amp;gt; Racheline analyzed the machine by hand in Feb 2025, validating the result and provided the step estimate listed above.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1331570843829932063/1337228898068463718&amp;lt;/ref&amp;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;steps. The TM was discovered by Pavel Kropitz in May 2024 &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;in &lt;/ins&gt;a group of 7 long-running halting BB(4,3) TMs.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&amp;lt;/ref&amp;gt; Racheline analyzed the machine by hand in Feb 2025, validating the result and provided the step estimate listed above.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1331570843829932063/1337228898068463718&amp;lt;/ref&amp;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;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;&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;Pavel listed the halting tape as:&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;Pavel listed the halting tape as:&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

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&lt;/table&gt;</summary>
		<author><name>Polygon</name></author>
	</entry>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=4679&amp;oldid=prev</id>
		<title>RobinCodes: Corrected the number of TMs found by Pavel</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=4679&amp;oldid=prev"/>
		<updated>2025-10-23T15:12:59Z</updated>

		<summary type="html">&lt;p&gt;Corrected the number of TMs found by Pavel&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;
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				&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 15:12, 23 October 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-l4&quot;&gt;Line 4:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 4:&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;&amp;lt;math display=&amp;quot;block&amp;quot;&amp;gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1}) \text{ and } 2 \uparrow\uparrow\uparrow (2^{2^{32}+1}+1)&amp;lt;/math&amp;gt;&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;&amp;lt;math display=&amp;quot;block&amp;quot;&amp;gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1}) \text{ and } 2 \uparrow\uparrow\uparrow (2^{2^{32}+1}+1)&amp;lt;/math&amp;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;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;steps. The TM was discovered by Pavel Kropitz in May 2024 as a group of &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;6 &lt;/del&gt;long-running halting BB(4,3) TMs.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&amp;lt;/ref&amp;gt; Racheline analyzed the machine by hand in Feb 2025, validating the result and provided the step estimate listed above.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1331570843829932063/1337228898068463718&amp;lt;/ref&amp;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;steps. The TM was discovered by Pavel Kropitz in May 2024 as a group of &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;7 &lt;/ins&gt;long-running halting BB(4,3) TMs.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&amp;lt;/ref&amp;gt; Racheline analyzed the machine by hand in Feb 2025, validating the result and provided the step estimate listed above.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1331570843829932063/1337228898068463718&amp;lt;/ref&amp;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;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;&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;Pavel listed the halting tape as:&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;Pavel listed the halting tape as:&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

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&lt;/table&gt;</summary>
		<author><name>RobinCodes</name></author>
	</entry>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=4249&amp;oldid=prev</id>
		<title>Polygon: Added Category:BB(4,3)</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=4249&amp;oldid=prev"/>
		<updated>2025-10-04T11:00:52Z</updated>

		<summary type="html">&lt;p&gt;Added Category:BB(4,3)&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 11:00, 4 October 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-l87&quot;&gt;Line 87:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 87:&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;== References ==&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;== References ==&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;&amp;lt;references /&amp;gt;&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;&amp;lt;references /&amp;gt;&lt;/div&gt;&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;[[Category:BB(4,3)]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

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&lt;/table&gt;</summary>
		<author><name>Polygon</name></author>
	</entry>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=3255&amp;oldid=prev</id>
		<title>Polygon: Added upper bound</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=3255&amp;oldid=prev"/>
		<updated>2025-08-18T13:58:20Z</updated>

		<summary type="html">&lt;p&gt;Added upper bound&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 13:58, 18 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 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;{{machine|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD}}&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;{{machine|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD}}&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;{{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is a halting [[BB(4,3)]] machine that appears to run for &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;around&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;{{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is a halting [[BB(4,3)]] machine that appears to run for &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;between&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;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;&amp;lt;math display=&quot;block&quot;&amp;gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1})&amp;lt;/math&amp;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;&amp;lt;math display=&quot;block&quot;&amp;gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1}&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;) \text{ and } 2 \uparrow\uparrow\uparrow (2^{2^{32}+1}+1&lt;/ins&gt;)&amp;lt;/math&amp;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;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;&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;steps. The TM was discovered by Pavel Kropitz in May 2024 as a group of 6 long-running halting BB(4,3) TMs.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&amp;lt;/ref&amp;gt; Racheline analyzed the machine by hand in Feb 2025, validating the result and provided the step estimate listed above.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1331570843829932063/1337228898068463718&amp;lt;/ref&amp;gt;&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;steps. The TM was discovered by Pavel Kropitz in May 2024 as a group of 6 long-running halting BB(4,3) TMs.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&amp;lt;/ref&amp;gt; Racheline analyzed the machine by hand in Feb 2025, validating the result and provided the step estimate listed above.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1331570843829932063/1337228898068463718&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Polygon</name></author>
	</entry>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=3247&amp;oldid=prev</id>
		<title>Polygon: It&#039;s actually slightly larger</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=3247&amp;oldid=prev"/>
		<updated>2025-08-18T10:30:10Z</updated>

		<summary type="html">&lt;p&gt;It&amp;#039;s actually slightly larger&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 10:30, 18 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-l2&quot;&gt;Line 2:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 2:&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;{{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is a halting [[BB(4,3)]] machine that appears to run for around&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;{{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is a halting [[BB(4,3)]] machine that appears to run for around&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;&amp;lt;math display=&quot;block&quot;&amp;gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1}&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;-1&lt;/del&gt;)&amp;lt;/math&amp;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;&amp;lt;math display=&quot;block&quot;&amp;gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1})&amp;lt;/math&amp;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;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;&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;steps. The TM was discovered by Pavel Kropitz in May 2024 as a group of 6 long-running halting BB(4,3) TMs.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&amp;lt;/ref&amp;gt; Racheline analyzed the machine by hand in Feb 2025, validating the result and provided the step estimate listed above.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1331570843829932063/1337228898068463718&amp;lt;/ref&amp;gt;&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;steps. The TM was discovered by Pavel Kropitz in May 2024 as a group of 6 long-running halting BB(4,3) TMs.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&amp;lt;/ref&amp;gt; Racheline analyzed the machine by hand in Feb 2025, validating the result and provided the step estimate listed above.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1331570843829932063/1337228898068463718&amp;lt;/ref&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Polygon</name></author>
	</entry>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=3022&amp;oldid=prev</id>
		<title>Polygon: Removed excess line</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=3022&amp;oldid=prev"/>
		<updated>2025-08-11T09:53:55Z</updated>

		<summary type="html">&lt;p&gt;Removed excess line&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 09:53, 11 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 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;{{machine|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD}}&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;{{machine|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD}}&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;&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;{{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is a halting [[BB(4,3)]] machine that appears to run for around&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;{{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is a halting [[BB(4,3)]] machine that appears to run for around&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;!-- diff cache key mediawiki:diff:1.41:old-1515:rev-3022:php=table --&gt;
&lt;/table&gt;</summary>
		<author><name>Polygon</name></author>
	</entry>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=1515&amp;oldid=prev</id>
		<title>Racheline at 14:36, 8 February 2025</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=1515&amp;oldid=prev"/>
		<updated>2025-02-08T14:36:36Z</updated>

		<summary type="html">&lt;p&gt;&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 14:36, 8 February 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-l82&quot;&gt;Line 82:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 82:&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;== Equivalent TMs ==&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;== Equivalent TMs ==&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;The TMs {{TM|0RB1RZ1RC_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}}, {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ0RA|halt}}, {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ1RB|halt}} are equivalent to {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}}, with the exact same halting configuration &amp;lt;code&amp;gt;0^inf 1 2^(σ-10) 101211 Z&amp;gt; 1221 0^inf&amp;lt;/code&amp;gt;, where &amp;lt;code&amp;gt;σ = 5*2^(2^(f^g^n1(n0)(0)+1)+2)+7&amp;lt;/code&amp;gt; is the total number of nonzero symbols.&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;The TMs {{TM|0RB1RZ1RC_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}}, {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ0RA|halt}}, {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ1RB|halt}} &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;[https://discord.com/channels/960643023006490684/1331570843829932063/1337236324846927932 &lt;/ins&gt;are equivalent&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;] &lt;/ins&gt;to {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}}, with the exact same halting configuration &amp;lt;code&amp;gt;0^inf 1 2^(σ-10) 101211 Z&amp;gt; 1221 0^inf&amp;lt;/code&amp;gt;, where &amp;lt;code&amp;gt;σ = 5*2^(2^(f^g^n1(n0)(0)+1)+2)+7&amp;lt;/code&amp;gt; is the total number of nonzero symbols.&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;To see that {{TM|0RB1RZ1RC_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is equivalent, simply notice that the situation &amp;lt;code&amp;gt;A&amp;gt; 20&amp;lt;/code&amp;gt; never occurs in any of the rules in the above analysis, or inside the low-level bell cycles, and that &amp;lt;code&amp;gt;A&amp;gt; 21&amp;lt;/code&amp;gt; and &amp;lt;code&amp;gt;A&amp;gt; 22&amp;lt;/code&amp;gt; behave the same in both TMs, except that they take two more steps in {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}}. Since the A2 transition is the only difference between the two, this means the TMs only differ in the number of steps it takes to halt (and even that difference is insignificant, on the order of σ = &amp;lt;code&amp;gt;5*2^(2^(f^g^n1(n0)(0)+1)+2)+7&amp;lt;/code&amp;gt; while the total number of steps is around σ&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;. {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ0RA|halt}} and {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ1RB|halt}} are just {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} and {{TM|0RB1RZ1RC_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} respectively, but started one step later, so that their halting time is 1 step smaller.&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;To see that {{TM|0RB1RZ1RC_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is equivalent, simply notice that the situation &amp;lt;code&amp;gt;A&amp;gt; 20&amp;lt;/code&amp;gt; never occurs in any of the rules in the above analysis, or inside the low-level bell cycles, and that &amp;lt;code&amp;gt;A&amp;gt; 21&amp;lt;/code&amp;gt; and &amp;lt;code&amp;gt;A&amp;gt; 22&amp;lt;/code&amp;gt; behave the same in both TMs, except that they take two more steps in {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}}. Since the A2 transition is the only difference between the two, this means the TMs only differ in the number of steps it takes to halt (and even that difference is insignificant, on the order of σ = &amp;lt;code&amp;gt;5*2^(2^(f^g^n1(n0)(0)+1)+2)+7&amp;lt;/code&amp;gt; while the total number of steps is around σ&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;)&lt;/ins&gt;. {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ0RA|halt}} and {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ1RB|halt}} are just {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} and {{TM|0RB1RZ1RC_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} respectively, but started one step later, so that their halting time is 1 step smaller.&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;&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;== References ==&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;== References ==&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;&amp;lt;references /&amp;gt;&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;&amp;lt;references /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Racheline</name></author>
	</entry>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=1511&amp;oldid=prev</id>
		<title>Racheline at 14:26, 8 February 2025</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=1511&amp;oldid=prev"/>
		<updated>2025-02-08T14:26:57Z</updated>

		<summary type="html">&lt;p&gt;&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 14:26, 8 February 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-l79&quot;&gt;Line 79:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 79:&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;this continues the same way as if the 0^8 was a 0^10 until the last few steps, so the tape differs from 0^inf 1 &amp;lt;D 0^2 2^(5*2^(2^(f^g^n1(n0)(0)+1)+2)-4) 11221 in a small amount of symbols on the left end and the right end, which you can easily count by running a smaller example&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;this continues the same way as if the 0^8 was a 0^10 until the last few steps, so the tape differs from 0^inf 1 &amp;lt;D 0^2 2^(5*2^(2^(f^g^n1(n0)(0)+1)+2)-4) 11221 in a small amount of symbols on the left end and the right end, which you can easily count by running a smaller example&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;&amp;lt;/pre&amp;gt;&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;&amp;lt;/pre&amp;gt;&lt;/div&gt;&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;&lt;/ins&gt;&lt;/div&gt;&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;== Equivalent TMs ==&lt;/ins&gt;&lt;/div&gt;&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;&lt;/ins&gt;&lt;/div&gt;&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;The TMs {{TM|0RB1RZ1RC_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}}, {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ0RA|halt}}, {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ1RB|halt}} are equivalent to {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}}, with the exact same halting configuration &amp;lt;code&amp;gt;0^inf 1 2^(σ-10) 101211 Z&amp;gt; 1221 0^inf&amp;lt;/code&amp;gt;, where &amp;lt;code&amp;gt;σ = 5*2^(2^(f^g^n1(n0)(0)+1)+2)+7&amp;lt;/code&amp;gt; is the total number of nonzero symbols.&lt;/ins&gt;&lt;/div&gt;&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;&lt;/ins&gt;&lt;/div&gt;&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;To see that {{TM|0RB1RZ1RC_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is equivalent, simply notice that the situation &amp;lt;code&amp;gt;A&amp;gt; 20&amp;lt;/code&amp;gt; never occurs in any of the rules in the above analysis, or inside the low-level bell cycles, and that &amp;lt;code&amp;gt;A&amp;gt; 21&amp;lt;/code&amp;gt; and &amp;lt;code&amp;gt;A&amp;gt; 22&amp;lt;/code&amp;gt; behave the same in both TMs, except that they take two more steps in {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}}. Since the A2 transition is the only difference between the two, this means the TMs only differ in the number of steps it takes to halt (and even that difference is insignificant, on the order of σ = &amp;lt;code&amp;gt;5*2^(2^(f^g^n1(n0)(0)+1)+2)+7&amp;lt;/code&amp;gt; while the total number of steps is around σ&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;. {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ0RA|halt}} and {{TM|1RB1LA2LA_1LA2RC1LB_1RD2RB0LC_0RA1RZ1RB|halt}} are just {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} and {{TM|0RB1RZ1RC_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} respectively, but started one step later, so that their halting time is 1 step smaller.&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;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;&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;== References ==&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;== References ==&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;&amp;lt;references /&amp;gt;&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;&amp;lt;references /&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;

&lt;!-- diff cache key mediawiki:diff:1.41:old-1508:rev-1511:php=table --&gt;
&lt;/table&gt;</summary>
		<author><name>Racheline</name></author>
	</entry>
	<entry>
		<id>https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=1508&amp;oldid=prev</id>
		<title>Sligocki: Created page with &quot;{{machine|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD}}  {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is a halting BB(4,3) machine that appears to run for around  &lt;math display=&quot;block&quot;&gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1}-1)&lt;/math&gt;  steps. The TM was discovered by Pavel Kropitz in May 2024 as a group of 6 long-running halting BB(4,3) TMs.&lt;ref&gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&lt;/ref&gt; Racheline analyzed the ma...&quot;</title>
		<link rel="alternate" type="text/html" href="https://wiki.bbchallenge.org/w/index.php?title=0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD&amp;diff=1508&amp;oldid=prev"/>
		<updated>2025-02-07T19:47:58Z</updated>

		<summary type="html">&lt;p&gt;Created page with &amp;quot;{{machine|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD}}  {{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is a halting &lt;a href=&quot;/wiki/BB(4,3)&quot; title=&quot;BB(4,3)&quot;&gt;BB(4,3)&lt;/a&gt; machine that appears to run for around  &amp;lt;math display=&amp;quot;block&amp;quot;&amp;gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1}-1)&amp;lt;/math&amp;gt;  steps. The TM was discovered by Pavel Kropitz in May 2024 as a group of 6 long-running halting BB(4,3) TMs.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&amp;lt;/ref&amp;gt; Racheline analyzed the ma...&amp;quot;&lt;/p&gt;
&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;{{machine|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD}}&lt;br /&gt;
&lt;br /&gt;
{{TM|0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD|halt}} is a halting [[BB(4,3)]] machine that appears to run for around&lt;br /&gt;
&lt;br /&gt;
&amp;lt;math display=&amp;quot;block&amp;quot;&amp;gt;2 \uparrow\uparrow\uparrow (2^{2^{32}+1}-1)&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
steps. The TM was discovered by Pavel Kropitz in May 2024 as a group of 6 long-running halting BB(4,3) TMs.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1026577255754903572/1243253180297646120&amp;lt;/ref&amp;gt; Racheline analyzed the machine by hand in Feb 2025, validating the result and provided the step estimate listed above.&amp;lt;ref&amp;gt;https://discord.com/channels/960643023006490684/1331570843829932063/1337228898068463718&amp;lt;/ref&amp;gt;&lt;br /&gt;
&lt;br /&gt;
Pavel listed the halting tape as:&lt;br /&gt;
&lt;br /&gt;
&amp;lt;pre&amp;gt;&lt;br /&gt;
1 2^((80*2^((&amp;lt;(8*2^((8*2^(29) - 2)) - 5); (&amp;lt;(80*2^((b - 10)/5) - 17)/9; (40*2^((8*2^((a - 11)/5) - 2)) - 4); (40*2^(2) - 4)&amp;gt; + 4); (&amp;lt;(80*2^((&amp;lt;(80*2^((8*2^((8*2^(29) - 2)) - 3)) - 13)/9; (40*2^((8*2^((a - 11)/5) - 2)) - 4); (40*2^(2) - 4)&amp;gt; - 6)/5) - 17)/9; (40*2^((8*2^((a - 11)/5) - 2)) - 4); (40*2^(2) - 4)&amp;gt; + 4)&amp;gt; - 10)/5) - 3)) 1 0 1 2 1^2 Z&amp;gt; 1 2^2 1&lt;br /&gt;
&amp;lt;/pre&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== Analysis by racheline ==&lt;br /&gt;
https://discord.com/channels/960643023006490684/1331570843829932063/1337228898068463718&lt;br /&gt;
&lt;br /&gt;
&amp;lt;pre&amp;gt;&lt;br /&gt;
f(n) = 2^2^(n+1)&lt;br /&gt;
g(n) = (5*2^(2^(f^n(0)+1)+2)-8)/9&lt;br /&gt;
n0 = (5*2^(2^(2^32+1)+1)-4)/9&lt;br /&gt;
n1 = 2^(2^32+1)-4&lt;br /&gt;
0RB1RZ0RB_1RC1LB2LB_1LB2RD1LC_1RA2RC0LD halts with 5*2^(2^(f^g^n1(n0)(0)+1)+2)+7 nonzero symbols on the tape, after roughly (that)^2 steps&lt;br /&gt;
that&amp;#039;s around 2^^^(2^(2^32+1)-1)&lt;br /&gt;
the rules necessary for verification:&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5n) 2^4 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^n+2)&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5n+2) 2^5 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^(n+1))&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5n) 221122 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^n+4)&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5n+4) 1 0^5 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^23 1 0^(5*2^(n+2)-22) 1011221&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5n) 1 0^10 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(5*2^(n+1)) 11221&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5n+2) 2222112 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^(n+1)+2)&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5n+2) 21 0^10 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(5*2^(n+2)-4) 11221&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5n+2) 2^9 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^(n+1)) 2^4 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^2^(n+1)+2) =&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5f(n)+2)&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(9n) -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5f^n(0)+2)&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(9n+4) 11221 0^10 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5f^n(0)+2) 222211221 0^10 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^(f^n(0)+1)+2) 21 -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(5*2^(2^(f^n(0)+1)+2)-4) 11221 =&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(9g(n)+4) 11221&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(9n+4) 11221 0^(10m) -&amp;gt;&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(9g^m(n)+4) 11221&lt;br /&gt;
&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^16 11221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^10 2^11 11221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^22 2^7 11221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^160 2211221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^32+4) 1 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^23 1 0^(5*2^(2^32+2)-22) 1011221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^10 2^18 1 0^(5*2^(2^32+2)-22) 1011221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^22 2^14 1 0^(5*2^(2^32+2)-22) 1011221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^160 2^9 1 0^(5*2^(2^32+2)-22) 1011221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^32+2) 2^5 1 0^(5*2^(2^32+2)-22) 1011221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^(2^32+1)) 1 0^(5*2^(2^32+2)-22) 1011221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(5*2^(2^(2^32+1)+1)) 11221 0^(5*2^(2^32+2)-32) 1011221 0^inf =&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(9n0+4) 11221 0^(10n1+8) 1011221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^2 2^(9g^n1(n0)+4) 11221 0^8 1011221 0^inf&lt;br /&gt;
0^inf 1 &amp;lt;D 0^(5*2^(f^g^n1(n0)(0)+1)+2) 21 0^8 1011221 0^inf&lt;br /&gt;
this continues the same way as if the 0^8 was a 0^10 until the last few steps, so the tape differs from 0^inf 1 &amp;lt;D 0^2 2^(5*2^(2^(f^g^n1(n0)(0)+1)+2)-4) 11221 in a small amount of symbols on the left end and the right end, which you can easily count by running a smaller example&lt;br /&gt;
&amp;lt;/pre&amp;gt;&lt;br /&gt;
&lt;br /&gt;
== References ==&lt;br /&gt;
&amp;lt;references /&amp;gt;&lt;/div&gt;</summary>
		<author><name>Sligocki</name></author>
	</entry>
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