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Topic: group theory proof
Replies: 1   Last Post: Aug 20, 2011 6:50 AM

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Posts: 19
Registered: 1/13/11
group theory proof
Posted: Jul 20, 2011 1:19 PM
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Let A and B be sets. Prove: If AXB (A cross B)is a group, then A is a normal subgroup of AXB.

I don't even know how to start. I now that in order to be a NORMAL subgroup, the left and right cosets of A must be the same. How do you show that algebraically?

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