Set Theory Unit
Set theory is a branch of mathematical logic that studies sets, which informally are collections of objects.  Although any type of object can be collected into a set, set theory is applied most often to objects that are relevant to mathematics.  
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Georg Cantor (1845 - 1918)
A single paper written in 1874 by Georg Cantor founded the modern study of set theory.  The paper was called “On a Property of the Collection of All Real Algebraic Numbers”.  The next wave of excitement in set theory came around 1900, when it was discovered that some interpretations of Cantor’s work on set theory gave rise to several contradictions, called paradoxes.  Fortunately, the debate surrounding the paradoxes in Cantor’s set theory did not lead to its abandonment.  Instead, the work of Ernst Zermelo and Abraham Fraenkel resulted in a set of axioms in order to formulate a theory of sets free of paradoxes such as the paradoxes found in Cantor’s work.
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