User:Juan Marquez/HNN-extensions

Z_2*_{Z_2}Z_2

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am I sure that   is equal to  ? Not yet...

but, it is solved so...

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We have for the HNN-extension:  .

Which in the case   will give us

 

For the trivial homomorphism   we have

 

Which shows indeed that   is factorizable within finite groups

oops!

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In fact that we've just seen is that   because we have used the only two group-morphism   in the definition of amalgamated free product


symbolic

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