Matrix $A$, $B$ and $C$ are symmetric Toeplitz matrices with $n$ by $n$ size, where $A$ and $C$ are positive definite matrices and $B$ or $(-B)$ is positive definite matrix, too. $R$ is a $2n$ by $2n$ matrix, and can be expressed as

$$R= \begin{pmatrix}
A & B \\
B & C 
\end{pmatrix}$$

And one konwn condition is

![enter image description here](https://i.stack.imgur.com/uvtxF.png)

For each number in these matrixes, it has

![enter image description here](https://i.stack.imgur.com/xdxyI.png)

Is $R$ a positive definite matrix?