Matrix with Varying Font Sizes

Here is an example of how to create a matrix with varying font sizes in Collabora Office Math. You can copy this example to the Commands 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]