In section 3, we split the vector B into two uncorrelated components, as
We further decompose 
, and write
The three components on the right hand side of the above equation are mutually
uncorrelated. We may partition 
, the `unresolved variation' from the
adjustment by D, as
The second term is the adjusted variance matrix of B by 
, and
the first is the (partial) resolved variance matrix of B by F given
D, namely
Resolved variances are additive in the sense that
For any 
, we assess the further reduction in `residual
variation' from adding F, given D, as the (partial) resolution,
namely
