What is default continuation discount?
0.9^3=0.729.
What is interrupted review-release value?
-1-0.9=-1.9, without continuation.
Why is transfer continuation contribution 2 rather than 4?
The transfer option takes 2 steps, so its continuation value 8 is discounted by 0.5^2=0.25, not 0.5, and contributes 8(0.25)=2 rather than 8(0.5)=4.