How to show $\langle x,y \mid x^3=y^3=(xy)^3=1 \rangle$ is presentation of an infinite group?

This is a result in textbook, but I do not understand the rationale.


marked as duplicate by Dietrich Burde, Derek Holt group-theory Sep 13 '16 at 15:47

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • $\begingroup$ What was the given rationale that you do not understand? $\endgroup$ – Paul Plummer Sep 13 '16 at 14:37
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    $\begingroup$ Also this question is already here. $\endgroup$ – Paul Plummer Sep 13 '16 at 14:44