${\displaystyle I(x)=\log \frac{1}{p(x)}=-\log p(x)}$

EXAMPLE Let $\left\{a,b,c\right\}$ be a set of three events and let $p(a)=\mathrm{0,5}$, $p(b)=\mathrm{0,25}$ and $p(c)=\mathrm{0,25}$ be the probabilities of their occurrences. The information contents of these events are: $I(a)=\mathrm{lb}\frac{1}{\mathrm{0,50}}\mathrm{Sh}=1\mathrm{Sh}$, $I(b)=\mathrm{lb}\frac{1}{\mathrm{0,25}}\mathrm{Sh}=2\mathrm{Sh}$, $I(c)=\mathrm{lb}\frac{1}{\mathrm{0,25}}\mathrm{Sh}=2\mathrm{Sh}$.

Note 1 to entry: For a set of equiprobable events, the information content of each event is equal to the decision content of the set.