# $x\langle S\rangle x^{-1}=\langle S\rangle$ proof from group theory notes

This is lemma 1.13 of these lecture notes. The group theory text. But I don't see it is so obvious.

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Please don't leave your question in the title alone. And please provide more details to your question (there is no question right now, just a statement). –  mrf Sep 12 '13 at 20:18
Please, include a direct link or picture of what you want, it is impossible to find your lemma in that list. –  Pedro Tamaroff Sep 12 '13 at 20:22
Please make your question self-contained. The fact you are after is not true in general, although presumably it is true in the specific context you are in. –  user1729 Sep 12 '13 at 20:24

Of course the teacher means $x\langle S\rangle x^{-1}=\langle xS x^{-1}\rangle$.

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Agreed. From the generalization, it's clear this is merely a typing error. –  Rebecca J. Stones Sep 12 '13 at 20:37
@Rebecca: Thank you. –  Boris Novikov Sep 12 '13 at 20:41