How do I write a letter like : A ,with a bar over it ( stands for the closure of A in topology) . I looked it up but \={A} didn't work , see : $\={A}$ .Help

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    $\begingroup$ For single letter, you can use \bar ( eg, \bar{A} $\to \bar{A}$). For putting a line over multiple letters, use \overline instead (e.g. \overline{ABC} $\to \overline{ABC}$). $\endgroup$ – achille hui May 25 at 1:37
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    $\begingroup$ See the apt discussion of such accents and diacritical marks in Section 14 of the Question body for MathJax basic tutorial and quick reference, a good place for seeking similar tips and techniques. $\endgroup$ – hardmath May 25 at 3:18
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    $\begingroup$ I'm curious as to where the \= idea came from... $\endgroup$ – Asaf Karagila May 25 at 5:32
  • $\begingroup$ Text symbols ! ,short list (item 12 $\endgroup$ – StuartMN May 25 at 5:47


reads as


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    $\begingroup$ works also without the brackets: \overline A $\endgroup$ – elli saba May 25 at 1:29
  • $\begingroup$ Thanks for the help $\endgroup$ – StuartMN May 25 at 5:39

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