http://wiki.karljones.com/index.php?action=history&feed=atom&title=Theory_%28mathematical_logic%29 2026-10-23T17:21:29Z Revision history for this page on the wiki MediaWiki 1.24.2 http://wiki.karljones.com/index.php?title=Theory_(mathematical_logic)&diff=18279&oldid=prev 2016-09-13T15:55:12Z

<p></p> <table class='diff diff-contentalign-left'> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr style='vertical-align: top;'> <td colspan='2' style="background-color: white; color:black; text-align: center;">← Older revision</td> <td colspan='2' style="background-color: white; color:black; text-align: center;">Revision as of 15:55, 13 September 2016</td> </tr><tr><td colspan="2" class="diff-lineno">Line 12:</td> <td colspan="2" class="diff-lineno">Line 12:</td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>* [[Axiomatic system]]</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>* [[Axiomatic system]]</div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; 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;"><div><ins style="font-weight: bold; text-decoration: none;">* [[Deductive system]]</ins></div></td></tr> <tr><td colspan="2">&#160;</td><td class='diff-marker'>+</td><td style="color:black; 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;"><div><ins style="font-weight: bold; text-decoration: none;">* [[Formal system]]</ins></div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>* [[List of first-order theories]]</div></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"><div>* [[List of first-order theories]]</div></td></tr> <tr><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'>&#160;</td><td style="background-color: #f9f9f9; color: #333333; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #e6e6e6; vertical-align: top; white-space: pre-wrap;"></td></tr> </table>

Karl Jones http://wiki.karljones.com/index.php?title=Theory_(mathematical_logic)&diff=18278&oldid=prev 2016-09-13T15:48:34Z

<p>Created page with &quot;In <a href="/index.php/Mathematical_logic" title="Mathematical logic">mathematical logic</a>, a &#039;&#039;&#039;theory&#039;&#039;&#039; (also called a &#039;&#039;&#039;formal theory&#039;&#039;&#039;) is a set of sentences in a <a href="/index.php/Formal_language" title="Formal language">formal language</a>. Usually a <a href="/index.php/Deductive_system" title="Deductive system">deductive system</a> is understood fro...&quot;</p> <p><b>New page</b></p><div>In [[mathematical logic]], a '''theory''' (also called a '''formal theory''') is a set of sentences in a [[formal language]].<br /> <br /> Usually a [[deductive system]] is understood from context.<br /> <br /> An element ϕ ∈ T of a theory T is then called an axiom of the theory, and any sentence that follows from the axioms ( T ⊢ ϕ is called a theorem of the theory.<br /> <br /> Every axiom is also a theorem. <br /> <br /> A [[first-order theory]] is a set of first-order sentences.<br /> <br /> == See also ==<br /> <br /> * [[Axiomatic system]]<br /> * [[List of first-order theories]]<br /> <br /> == External links ==<br /> <br /> * [https://en.wikipedia.org/wiki/Theory_(mathematical_logic) Theory (mathematical logic)] @ Wikipedia.org <br /> <br /> [[Category:Logic]]<br /> [[Category:Mathematics]]</div>

Karl Jones