I need to prove that [tex]-(-A)=A[/tex]. I guess it's the same as [tex]S-(S-A)=A[/tex], where [tex]S[/tex] is the space. So is it true, that if [tex]x \in S-(S-A)[/tex] then [tex]x \notin S-A[/tex]?(adsbygoogle = window.adsbygoogle || []).push({});

- Kamataat

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# Simple set question

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