Please see the image below.
What does the bar symbol mean in this context?
$\endgroup$ 31 Answer
$\begingroup$The complement of the set $B$, also commonly denoted as $B'$ or $B^c$. It is the set:
$$\bar{B} = B^c = B' = \{x \mid x \not \in B\}$$
$\endgroup$ 1
