# Review

• logical descriptions of maps
• series of definitions of the form $[\mathrm{F}]_o(x) = \begin{array}[t]{l} \mathtt{if}~\mathrm{(condition 1)}(x)~\mathtt{then}~{\top/\bot}~\mathtt{else}\\ \mathtt{if}~\mathrm{(condition 2)}(x)~\mathtt{then}~{\top/\bot}~\mathtt{else}\\ \vdots\\ [\mathrm{F}]_i(x) \end{array}$