Question 5 2009 AM Exam, Grinold Kroner

Why is it that if the Grinold Kroner Model subtracts the DeltaS (Stock repurchases) that in the Quesiton 5 2009 am exam it subtracts the ‘-.5’ instead of adding .5 (or subtracting the negative .5) (-(-.5)) Resulting in 4.5 instead of 3.5?

Because it’s an equity repurchase not a stock reprchase so you switch the sign