.I have to find this isomorphism:

Where and and is a well ordered increasing sequence of sub modules for .

What do you mean by "well-orderedincreasingseq. of submod. of..."?? That is indexed by a countable index set and thus , or

that for any two indexes , either ?only

Tonio

I know that it is something about sending the residue class into the pair of residue classes

But how to argue that this is a homomorphism?

And what would the kernel be?

Any help would be nice, thanks.