title: Can state in Proximal Policy Optimization contain history?
body: <p>For example can the State at timestep t actually be made of the state at t and t-1. </p>
  
  <pre><code>S_t = [s_t, s_t-1]
  </code></pre>
  
  <p>i.e. Does Proximal Policy Optimization already incorporate the state history, or can it be implicit in the State (or neither).</p>