 \operatorname{Tr}(C_{00} N) &= 0, \\ \operatorname{Tr}(C_{00} M) =0,\  \operatorname{Tr}(C_{00} N) &= 0, \\ \operatorname{Tr}(C_{00} M) =0,\  \operatorname{Tr}(C_{00} N) &= 0, \\ \operatorname{Tr}(C_{00}