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		<id>https://www.conservapedia.com/index.php?title=Set_theory&amp;diff=807956</id>
		<title>Set theory</title>
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		<updated>2010-08-19T23:29:46Z</updated>

		<summary type="html">&lt;p&gt;Purify2glorify: &lt;/p&gt;
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&lt;div&gt;'''Set theory''' is a branch of [[mathematics]] dealing with collections of objects.  &lt;br /&gt;
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*The language of set theory is based on a single fundamental relation, called membership. We say that A is a member of B (in symbols A  ∈ B), or that the set B contains A as its element. The understanding is that a set is determined by its elements; in other words, two sets are deemed equal if they have exactly the same elements. &amp;lt;ref&amp;gt;http://plato.stanford.edu/entries/set-theory/&amp;lt;/ref&amp;gt;&lt;br /&gt;
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==History of set theory==&lt;br /&gt;
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It was developed in the late 1800s, primarly by the German mathematician [[Georg Cantor]].  This initial attempt became known as &amp;quot;naive set theory&amp;quot; because mathematicians found flaws in it. It was replaced by &amp;quot;axiomatic set theory&amp;quot; in the early 1900s. The most commonly used such axiomatization is [[Zermelo-Fraenkel]] set theory.&lt;br /&gt;
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One paradox in naive set theory was announced by [[Bertrand Russell]] in 1901, and is known as [[Russell's Paradox]].&lt;br /&gt;
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Like all sufficiently strong mathematical theories, set theory is incomplete, as shown by [[Kurt Godel]].  However, set theory is the received axiomatization of mathematics today, with subjects like analysis, [[algebra]], topology, and [[geometry]] using set theory and its language for their own foundation.&lt;br /&gt;
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==The Empty Set==&lt;br /&gt;
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The empty set is the set with no members.  Because sets are uniquely defined by membership, the empty set is unique.  The empty set is usually denoted by {} or ∅.&lt;br /&gt;
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==References==&lt;br /&gt;
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&amp;lt;References/&amp;gt;&lt;br /&gt;
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[[Category: set theory]]&lt;/div&gt;</summary>
		<author><name>Purify2glorify</name></author>
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