Bijection between sets of functions

In summary, the conversation discusses the proof of a bijection between two sets: (X x Y)^Z and X^Z x Y^Z. The speaker mentions using a function S to show that psi is an injection, but they are struggling to prove that it is also a surjection. The other person offers a hint to define f(z) as (h(z),g(z)) and verify it as a counter image of (h,g).
  • #1
bedi
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0
For two sets X and Y let X^Y be the set of functions from Y to X.

Prove that there is a bijection between (X x Y)^Z and X^Z x Y^Z.

Attempt: I could not get any further from that "there must be a function S with S(f)=g and S(f')=g for any g, f' in X^Z x Y^Z, and where f is in (X x Y)^Z."
 
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  • #2
see attachment.
 

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  • #3
see attachment
 
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  • #4
Thank you, I think I'm done with proving that psi is an injection but I can't prove that it's also a surjection. Could you give me another hint?
 
  • #5
This is what I tried for surjectivity so far: psi is clearly a surjection, as for every ordered pair (h,g) there is an f such that psi(f)=(h,g), because when we look at the values of f, h and g at z we see that psi(x,y)=(x,y). But this is the identity function and therefore a surjection. Is that correct?
 
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  • #6
define f(z)=(h(z),g(z)).verify that this is a counter image of (h,g)
 

Related to Bijection between sets of functions

1. What is a bijection between sets of functions?

A bijection between sets of functions is a function that maps every element from one set to a unique element in another set, and vice versa. In other words, each element in one set has a corresponding and unique element in the other set.

2. How is a bijection different from other types of functions?

A bijection is different from other types of functions because it is both injective (one-to-one) and surjective (onto). This means that every element in the output set is mapped to by exactly one element in the input set, and every element in the output set is mapped from by at least one element in the input set.

3. What is the significance of a bijection between sets of functions?

A bijection between sets of functions is significant because it allows for a one-to-one correspondence between the elements of the two sets. This can be useful in various mathematical applications, such as proving the equality of two sets or finding the inverse of a function.

4. Can any two sets of functions have a bijection between them?

No, not all sets of functions have a bijection between them. For a bijection to exist, the two sets must have the same cardinality (number of elements). If one set has more or fewer elements than the other, a bijection cannot be established.

5. How is a bijection between sets of functions represented?

A bijection between sets of functions is typically represented using a mapping diagram or a two-column table. The input set is listed on the left side, and the output set is listed on the right side, with each element in the input set mapped to its corresponding element in the output set.

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