Value function (RL)

A value function is a mapping of states to a long term worth for a actor in a Markov decision process. This is defined by $V: S \rightarrow \mathbb{R}$.

Given you are acting along policy $\pi$ we can calculate the ideal value function to be

$$ > V^{\pi}(s) = \mathbb{E}[G_t \vert S_t = s]. > $$