Any idea what this could mean?

Computer Science Level 5

$\begin{array} { l l l l l l l l l } & & S & T & I & R & L & I & N & G \\ +& G & A & L & L & I & P & O & L & I \\ \hline & P & R & O & T & O & S & T & A & R \\ \hline \end{array}$

In the cryptarithm above, each letter represents a unique digit.

Find the value of $\overline{\text{GALOISRATS}}$

Read an interesting note on cryptarithms here