Изменения
→Сложение
<tex> \mathrm{R}\langle{}\mathrm{f},\mathrm{g}\rangle (x,y) = \left\{\begin{array}{ll}
\mathrm{f}(x) = x & y = 0\\
\mathrm{g}(x, y-1,\mathrm{R}\langle{}\mathrm{f},\mathrm{g}\rangle(x, y-1)) & y > 0
\end{array}\right. </tex>
