it’s optimal for them to spare and cooperate forever

But as delta approaches 1, they’ll do anything possible to avoid the pain of infinite triple limb consumption,
which means they’ll choose to spare each other.At some point in between they could go either way.
We can find out where that point is by writing the infinite series that represents each strategy,
setting them equal to each other,and solving for delta.That yields 1/3,
meaning that as long as Crispy and Chewy care about tomorrow at least 1/3 as much as today,
it’s optimal for them to spare and cooperate forever.