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I Have a question .. can any one help me ? True or false : Any ring has at least 2 units .

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    $\begingroup$ Is $\mathbb{Z}_2$ a ring? $\endgroup$ – Robert Z Oct 15 '19 at 14:58
  • $\begingroup$ $\mathbb Z_2$ should be right after $\mathbb Z$ on your list of "simple examples I could check before asking." $\endgroup$ – rschwieb Oct 15 '19 at 15:51
5
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Take as a ring $\mathbb{Z}/2\mathbb{Z}$

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  • $\begingroup$ That mean It have only one unit ?! $\endgroup$ – user619263 Oct 15 '19 at 15:33
  • $\begingroup$ @user619263 do you know how $\mathbb{Z}/2\mathbb{Z}$ look like? $\endgroup$ – user289143 Oct 15 '19 at 15:35
  • $\begingroup$ Class zero and class one $\endgroup$ – user619263 Oct 15 '19 at 15:44
  • $\begingroup$ @user619263 and what are the units? $\endgroup$ – user289143 Oct 15 '19 at 15:45
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    $\begingroup$ The only unit is one . $\endgroup$ – user619263 Oct 15 '19 at 16:26

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