Markov Decision Process Policy

Topics: Markov Decision Process

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(definition)

In the context of a Markov decision process (MDP), a policy is a mapping of every one of the MDP’s states to a a specific decision.

In other words, a policy tells us which decisions are taken on which state.

Policies are normally denoted by $r$, while the set of possible policies in a given MDP is denoted by $R$.

We can denote the decision taken in a state $i$ according to the policy $r$ with $d_i\{r\}$:

$$r=\left(d_0\{r\},d_1\{r\},\dots \right)$$