Properties of D For z,w ε D,


Proof We have D(z,w) = zw/w*z1. The first three are elementary consequences. For the fourth, observe that wz = (zw) = zw, and z*w1 = (z*w1)* = w*z1, so that D(w,z) = wz/z*w1 = zw/w*z1 = D(z,w).
