Cardinality Question from Basic Analysis. Thanks for any help.

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SUMMARY

The discussion centers on proving that if the cardinality of sets A and B is less than or equal to the cardinality of the reals (|A| ≤ |R| and |B| ≤ |R|), then the cardinality of their union (|A ∪ B|) is also less than or equal to the cardinality of the reals. The user is in a basic analysis class and is seeking clarification on the concept of cardinality and its arithmetic properties. The key takeaway is the understanding of 1-1 functions mapping sets to the reals as a foundational concept in cardinality.

PREREQUISITES
  • Understanding of cardinality in set theory
  • Familiarity with 1-1 functions and their properties
  • Basic knowledge of real numbers and their cardinality
  • Introduction to set operations, particularly unions
NEXT STEPS
  • Study the arithmetic of cardinal numbers, focusing on union operations
  • Learn about Cantor's theorem and its implications on cardinality
  • Explore the concept of bijections and their role in comparing cardinalities
  • Investigate the properties of infinite sets and their cardinalities
USEFUL FOR

Students in basic analysis, mathematicians interested in set theory, and anyone looking to deepen their understanding of cardinality and its implications in mathematics.

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Homework Statement


If the cardinality of A is less than or equal to the cardinality of the reals and the cardinality of B is less than or equal to the cardinality of the reals, I need to show that the cardinality of the union of A and B is less than or equal to the cardinality of the reals.

IE: Prove that if |A|</=|R| and |B|</=|R|, then |AUB|</=|R|.

Thanks for any help. I am in a basic analysis class, and we just started a small section on cardinality.


Homework Equations





The Attempt at a Solution


All I know is that based on my assumption, I know that there is a 1-1 function from A to the real numbers and another 1-1 function from B to the real numbers.
 
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