“…A huge amount of new expansion formulas, like those in Lemmas 2.4 and 2.5, for calculating ranks of matrices were established in the past several decades. These formulas are so ground-breaking in both theory and applications that people can employ them in simplifying various complicated matrix expressions or equalities occurring in statistics, while the results obtained can easily be represented as some simple rank equalities, range equalities or matrix equations; see, e.g., Tian (2007Tian ( , 2009Tian ( , 2010Tian ( , 2012Tian ( , 2013, Tian and Takane (2008) and Tian and Zhang (2011). In this note, we also use the matrix rank method to characterize relations between BLUEs of parametric functions under (1.1) and (1.2).…”