Negation

Definition: Negation

The negation function is the Boolean operator $\mathrm{NOT}:\{0,1\}\to \{0,1\}$ defined in the following way:

$$\mathrm{NOT}(x)\stackrel{\text{def}}{=}\{\begin{array}{l}0\text{if }x=1\\ 1\text{if }x=0\end{array}$$

NOTATION

It is much more common to write $\mathrm{NOT}(x)$ in one of the following ways:

$$\neg x!x\overline{x}$$