עזרה עבור LibreOffice 25.2
Here is an example of how to create a matrix with varying font sizes in \<emph\>LibreOffice Math\</emph\>. You can copy this example to the \<emph\>Commands\</emph\> window using the clipboard and use it in your own formula.
func G^{(%alpha" ," %beta)}_{ x_m x_n} = left[ matrix { arctan(%alpha) # arctan(%beta) ## x_m + x_n # x_m - x_n }right]