Set complement

Given a set \(A\subseteq X\) we define the set complement of \(A\) in \(X\) to be: $$ X - A $$ If the bigger set is clear from the context, we also write \(A^c\).

For example: For the set \(X= \{1, 2, 3, 4, 5\}\) and set \(A=\{1, 2\}\), \(A^c = \{3, 4, 5\}\).