Proving Abelian Group Structure in C^A

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Homework Statement



Typeset problem 1: Let A be an abelian group; define T^A as functions f: A to T with pointwise product (fg)(a) = [f(a)][g(a)] in C; prove it is an abelian group, including closure.



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The Attempt at a Solution



For the first question, since [f(a)][g(a)] is in C, can I just say that since C is a ring, it is an abelian group, then the four axioms are proven? Then just show closure? Probably not I'm guessing. Associativity of multiplying functions seems so fundamental to me that I really don't know what to do...

For the second question, shall I start by using composition of functions and then the properties of composition of a function and its inverse, and then go on about the identity function?
 
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  • Typed homework problem 1: Let A be an abelian group; define T^A as the set of functions from A to T, with pointwise multiplication (fg)(a) = [f(a)][g(a)] in C; prove it is an abelian group.
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  • Handwritten-style math problem: Let A be an abelian group. For each b in A and each character chi in the dual group A-hat, show that chi^(-1)(b) = [chi(b)]^(-1) = chi(b^(-1)) = conj(chi(b)). And chi(1) = 1.
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I'd say question one is asking you to flesh out the group structure.

1. What's the identity element? (make sure it's a member of C^A).

2. For each element f, what's the inverse element? (make sure it's well defined
- namely, why can you find f^-1 for each f? )

Closure is trivial but should be mentioned, namely why is (fg) a well
defined member of C^A when f and g are?

Associativity (and Abelian-ness) of course follow from the properties of C,
but you should have a proof showing f(gh) =(fg)h.

For question 2. I don't know what A-hat is. What do you know
about group homomorphisms at this point?