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How do I find an isomorphism between Sn+m and Zn x Zm?

  1. Mar 13, 2007 #1
    How do I find an isomorphism between Sn+m and Zn x Zm? provided n,m are not relatively prime? Thanks.
  2. jcsd
  3. Mar 14, 2007 #2


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    I dunno, place an ad in the classifieds, put up posters, etc. Or maybe start by defining what you even mean by Sn+m, because in the standard notation, Sn+m is a group that's generally not isomorphic to Zn x Zm. Also, post this in the homework section, follow the guidelines for posting homework, and when you start a new thread in the homework section, use the template that will be given to you.
  4. Mar 14, 2007 #3
    Hi, this isn't exactly a homework question... Anyways, rereading my question again, I made a mistake. It should be how do I find an isomorphism between A SUBGROUP in Sn+m and Zn x Zm. If it is specific cases like n,m = 2,2 I can figure it out. But how do I figure out a general form for the isomorphism?
  5. Mar 14, 2007 #4


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    If there are two subgroups H and K of a group G such that the intersection of H and K is trivial and hk=kh for all h in H, k in K, then the subgroup HK is isomorphic to HxK.
  6. Mar 15, 2007 #5
    ah, thanks, I think I have it figured out now!
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