\pretzelbigforce{}\pretzelbackup{}{\bf function} {\it Wurzel}({\it x}:{\bf real}):{\bf real};\pretzelforce{}\pretzelbackup{}{\bf var} {\it x0},\pretzelopt9{}{\it x1}:{\bf real};\pretzelforce{}
{\bf begin}\pretzelindent{}\pretzelforce{}{\bf if} {\it x}$\geq$0 {\bf then}\pretzelindent{}\pretzelforce{}
{\bf begin}\pretzelindent{}\pretzelforce{}{\it x1}\hbox{${}\mathrel{:=}{}$}{\it x};\pretzelforce{}{\bf repeat}\pretzelindent{}\pretzelforce{}{\it x0}\hbox{${}\mathrel{:=}{}$}{\it x1};\pretzelforce{}{\it x1}\hbox{${}\mathrel{:=}{}$}({\it x0}+{\it x}/{\it x0})/2;\pretzeloutdent{}\pretzelforce{}{\bf until} ({\it x0}+{\it abs}({\it x0}-{\it x1})={\it x0});\pretzelforce{}{\it Wurzel}\hbox{${}\mathrel{:=}{}$}{\it x1};\pretzeloutdent{}\pretzelforce{}{\bf end}\pretzeloutdent{}\pretzelforce{}{\bf else}\pretzelindent{}\pretzelforce{}
{\bf begin}\pretzelindent{}\pretzelforce{}{\bf writeln}({\tt 'Fehler: Wurzel ist komplex!'});\pretzeloutdent{}\pretzelforce{}{\bf end}\pretzeloutdent{};\pretzeloutdent{}\pretzelforce{}{\bf end};\hbox{$\{${{ Wurzel }}$\}$}