the $y$-$z$ plane allowing maximal violation of inequality (10) for the triplet state. As an example, take the choice $\vartheta_1 =0$, $\varphi_1 =\pi/2$, $\vartheta^{\prime}_{1}=-\pi/2$, $\varphi^{\prime}_{1}=\pi/2$, $\vartheta_2 =\pi/4$, $\varphi_2 =\pi/2$, $\vartheta^{\prime}_{2}=-\pi/4$, and $\varphi^{\prime}_{2}=\pi/2$. As may easily be checked, these values fulfill the equality $$\begin{aligned}
|&& \cos \vartheta_1 \cos\vartheta_2 + \cos\vartheta_1 
\cos\vartheta^{\prime}_{2} + \cos\vartheta^{\prime}_{1} \cos\vartheta_2  \nonumber  \\
&& - \cos\vartheta^{\prime}_{1} \cos\vartheta^{\prime}_{2}
- \sin\vartheta_1 \sin\vartheta_2 \cos(\varphi_1 - \varphi_2) \nonumber  \\
&& - \sin\vartheta_1 \sin\vartheta^{\prime}_{2} \cos(\varphi_1 - \varphi^{\prime}_{2})
- \sin\vartheta^{\prime}_{1} \sin\vartheta_2  \nonumber  \\
&& \times \cos(\varphi^{\prime}_{1} - \varphi_2) + \sin\vartheta^{\prime}_{1}
\sin\vartheta^{\prime}_{2} \cos(\varphi^{\prime}_{1} - \varphi^{\prime}_{2})|
= 2 \sqrt{2}.\end{aligned}$$ Actually, having established that there exist infinitely many sets of directions satisfying the equality (17) for the singlet state, it is immediate to see that the same hols for the above equality (19) corresponding to the triplet state. Indeed, comparing the expressions in Eqs. (17) and (19), it follows at once that if the set of directions $\vec{e}_1(\vartheta_1,\varphi_1)$, $\vec{e}\,^{\prime}_{1}(\vartheta^{\prime}_{1},\varphi^{\prime}_{1})$, $\vec{e}_2(\vartheta_2,\varphi_2)$, and $\vec{e}\,^{\prime}_{2}(\vartheta^{\prime}_{2}, \varphi^{\prime}_{2})$ fulfill the equality (17), then the set of directions $\vec{e}_1(-\vartheta_1,\varphi_1)$, $\vec{e}\,^{\prime}_{1}(-\vartheta^{\prime}_{1}, \varphi^{\prime}_{1})$, $\vec{e}_2(\vartheta_2,\varphi_2)$, and $\vec{e}\,^{\prime}_{2}(\vartheta^{\prime}_{2}, \varphi^{\prime}_{2})$ do satisfy the equality (19) \[alternatively, the set of directions $\vec{e}_1(\vartheta_1,\varphi_1)$, $\vec{e}\,^{\prime}_{1}(\vartheta^{\prime}_{1}, \varphi^{\prime}_{1})$, $\vec{e}_2(-\vartheta_2,\varphi_2)$, and $\vec{e}\,^{\prime}_{2}(-\vartheta^{\prime}_{2}, \varphi^{\prime}_{2})$ also will do\].

A reasoning similar to that developed for the 