Let $\varphi : = (1 + \sqrt{5}) / 2$ be the D2137: Basic real golden ratio such that
(i) | \begin{equation} \varphi_* : = 1 - \varphi \end{equation} |
Then
(1) | \begin{equation} \varphi = 1 + \frac{1}{\varphi} \end{equation} |
(2) | \begin{equation} \varphi_* = 1 + \frac{1}{\varphi_*} \end{equation} |