Cardinality of continuous functions

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SUMMARY

The cardinality of the set of all continuous real-valued functions from the interval [0,1] to the real numbers R is established as \(\aleph^{\aleph}\). This conclusion is derived using the Cantor-Bernstein theorem, which confirms that the cardinality of continuous functions is less than or equal to the cardinality of all functions from [0,1] to R, which is also \(\aleph^{\aleph}\). The discussion highlights that continuous functions can be determined by their values on the rational numbers, reinforcing the established cardinality.

PREREQUISITES
  • Understanding of cardinality in set theory
  • Familiarity with the Cantor-Bernstein theorem
  • Knowledge of continuous functions and their properties
  • Basic concepts of real analysis, particularly concerning functions from intervals to the reals
NEXT STEPS
  • Study the Cantor-Bernstein theorem in detail
  • Explore the concept of cardinality in set theory
  • Investigate the properties of continuous functions in real analysis
  • Learn about the implications of cardinality on function spaces
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Mathematicians, students of real analysis, and anyone interested in set theory and the properties of continuous functions.

talolard
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Homework Statement


What is the cardinality of the set of all continuous real valued functions [0,1] \rightarrow R.




The Attempt at a Solution


In words:
I will be using the Cantor Bernstien theorem. First the above set, let's call it A, is lesser then or equal to the set of all functions from R to R which has a cardinality of \aleph ^ \aleph
Also, the cardinality of all continuous functions [0,1] \rightarrow R. is lesser then or equal too the cardinality of the set of all functions, continuous and not continuous, from [0,1] \rightarrow R.
The cardinality of the segment [0,1] is \aleph and so the cardinality of all functions [0,1] \rightarrow R. is also \aleph ^ \aleph and so by the cantor bernsiten theorem the cardinality of A is also \aleph ^ \aleph

In formal math:
I use C to denote continuous functions.
\aleph ^ \aleph =|R^R| \geq |R^{C[0,1]}| = |C[0,1] \rightarrow R| = |R^{C[0,1]}| \leq |R^{[0,1]}|=\ \aleph ^ \aleph


Is this correct? and formal anough?
Thanks
Tal
 
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Ahhh I see my mistake already.
Is it enough to say that a coninuous function is determined by its values on Q. Therefore
C[0,1] \rightarrow R = R^{[0,1] \in Q}= \aleph
 

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