MHB Prove: 2ε{a,2,b} in Set Theory

AI Thread Summary
The discussion centers on proving that 2 is an element of the set {a, 2, b} within axiomatic set theory. Participants seek clarity on the definitions of the set notation "{a, 2, b}" and the membership symbol "ε." The set is defined as the union of {a, 2} and {b}, which can be expressed as {a, 2} ∪ {b}. A reference to a similar problem and its solution is mentioned, but external links are discouraged. The conversation emphasizes the importance of understanding set definitions and notation in axiomatic set theory.
solakis1
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Prove in any axiomatic set theory that:2ε{a,2,b} , where a,b are letters
 
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What is the definition of "{a, 2, b}" in "axiomatic set theory"? What is the definition of "ε"?
 
Country Boy said:
What is the definition of "{a, 2, b}" in "axiomatic set theory"? What is the definition of "ε"?

{a,2,b}={a,2}U{b}
 
solakis said:
{a,2,b}={a,2}U{b}
Or even better, starting from where you left off: [math]\{ a, 2 \} \cup \{ b \} = \left ( \{ a \} \cup \{ 2 \} \right ) \cup \{ b \}[/math]

-Dan
 
solakis said:
here is the solution for a similar problem given by seppel in MHF

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Please do not give a link to another site as a means of providing a solution, either by the author of the thread posted here, or by someone responding with a solution.
 
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