A Q-function that represents future behavior along possible paths allows an agent to choose greedily according to the combined value metric.

“Let's say we have such a decomposition. Then we could effectively act greedily with respect to this kind of to this combined metric. Right? Because if we uh have a c a Q_ function which tells us what if we go down this path, the the future will behave like this, we go down this path, it will behave like this, and this path will behave like this. Now we can uh be greedy again with respect to the Q_ function. So effectively the Q_ function fundamentally is a closure over the like”

“Over the path that the policy can take.”