Grinold Kroner model inconstitent in different Mocks

The formula is D/P - DS + i + g +P/E

Now in all the mocks I have fount until today, if DS is given as = -0,5 it resulted in - (-0,5) = 0.5 and if DS is given as = 0.5 it resulted in - 0.5

Not in the CFA 2009 Mock exam, DS is given as - 0.5 and in the formula remains -0,5 (not -(-0.5))

WHY?

They explain it well in this thread:

https://www.analystforum.com/forums/cfa-forums/cfa-level-iii-forum/91365683

Basically pay attention if they give you the % change in number of shares or the repurchase yield. The first has a negative sign in front of it, the second you just plug it in as given.

yes that’s right and make sense. thanks!