logical complement
In Boolean algebra, the logical complement or negation of a Boolean value is the opposite value, given by the following truth table:
A | -A --+--- T | F F | T
-A is also written as A with a bar over it or with a small vertical line hanging from the right-hand end of the "-" (LaTeX \neg) or as A'. In the C programming language, it is !A and in digital circuit design, /A.