just a few comments on the names of the different variables:

$A$ or $\overline{\underline{A}}$ ... a
$A^*$ or $\overline{\underline{A}}^*$ ... as
$\underline{A}$ ... al (from "A lower bar")
$\underline{A}^* ... als
$\overline{A} ... au (from "A upper bar")
$\overline{A}^* ... aus 

then simple combinations of different matrices, i.e.,
$A^*B$ ... asb
$CA^*B$ ... casb

$G_{ref}$ ... gref

$CA^*B \lfrac CA^*B$ ... casblcasb

and then it becomes arbitrarily confusing, i.e.,
$\overline{\underline{A}}^* (\underline{A}^* B F_{opt})^* \underline{A}^* B P_{opt}$ ... asalsbfoptsalsbpopt
