
1.6.18 Fields, Groups, Rings
Problem:
Are rings \( A \) and \( R \), where \( A \) is a set of complex matrices of the form \( \left(\begin{array}{cc}z & w \\ -\bar{W} & \bar{z}\end{array}\right) \), and \( R \) is a set of real matrices of the form
\[
\left(\begin{array}{cccc}
x & -y & -z & -t \\
y & x & -t & z \\
z & t & x & -y \\
t & -z & y & x
\end{array}\right) ?
\]