Given the two-dimensional torus $T^{2}$, parameterized in terms of the two real variables $x^{1} \in[0,2 \pi)$ and $x^{2} \in[0,2 \pi)$, consider its embedding into the threedimensional Euclidean space $\mathbb{R}^{3}$ with the metric $\delta=\operatorname{diag}(1,1,1)$ given by

$$\begin{align*}
f: T^{2} & \mapsto \mathbb{R}^{3}, \\
\left(x^{1}, x^{2}\right) & \mapsto\left(\begin{array}{l}
A \cos x^{1}+B \cos x^{1} \cdot \cos x^{2} \\
A \sin x^{1}+B \sin x^{1} \cdot \cos x^{2} \\
B \sin x^{2}
\end{array}\right) \tag{5.392}
\end{align*}$$

with $0