For two operators Â( R) and B( R), one cannot compute the trace of a product of operators Tr e [ Â B] as Eq. 42). To get the separate S-W transform of Â and B, it is required to use two matching values of the radius, r s and r s, with complementing indices s and s which will be defined in Eq. 39. It can be shown that the S-W transform has the following property