Prove Isomorphism: R x S & S x R

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Homework Statement



Show that for any rings R and S, R x S and S x R are isomorphic, and A x B is the cartesian product, or ordered pairs. So an element of R x S can be written as (r1, s1).

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The Attempt at a Solution



So I have to show that there is a bijection from R x S to S x R, and this bijection must preserve addition and multiplication. This is tough for me since the mapping from R x S to S x R could be anything! How can I even start if I don't have this function or mapping?
 
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hi stripes! :smile:
stripes said:
… the mapping from R x S to S x R could be anything!

yes it could

but you're in charge, and you can choose any mapping you like :smile:

go for the "natural" mapping …

what do you think it would be really neat for (r1, s1) to be mapped onto? :wink:
 
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