The Agent-Environment Interaction figure from Reinforcement Learning: An Introduction by Richard S. Sutton and Andrew G. Barto reproduced in Tikz

Agent-Environment Interaction

\documentclass{standalone}
\usepackage{tikz}
\begin{document}
\tikzstyle{block} = [rectangle, draw, 
    text width=8em, text centered, rounded corners, minimum height=4em]
    
\tikzstyle{line} = [draw, -latex]

\begin{tikzpicture}[node distance = 6em, auto, thick]
    \node [block] (Agent) {Agent};
    \node [block, below of=Agent] (Environment) {Environment};
    
     \path [line] (Agent.0) --++ (4em,0em) |- node [near start]{Action $a_t$} (Environment.0);
     \path [line] (Environment.190) --++ (-6em,0em) |- node [near start] {New state  $s_{t+1}$} (Agent.170);
     \path [line] (Environment.170) --++ (-4.25em,0em) |- node [near start, right] {Reward $r_{t+1}$} (Agent.190);
\end{tikzpicture}
\end{document}

Thanks!!!

Thanks

Thank you.

Thanks for the sharing!

Awesome! With much thanks!

What does Environment.190 mean?

Merci!

See also https://tex.stackexchange.com/questions/461312/help-to-reproduce-a-diagram-in-tikz

A thousand thanks!