title: How to evaluate a cyclic directed graph of functions?
body: <p>I have a cyclic directed graph of functions. I plan to use this graph to control a robot as in the famous Karl Sims experiments about evolving a virtual creature:</p>
  
  <p><a href="http://www.karlsims.com" rel="nofollow noreferrer">http://www.karlsims.com</a>
  <img src="https://i.stack.imgur.com/TjlBl.jpg" alt="Karl Sims evolving virtual creature ANN"></p>
  
  <p>However I cannot imagine a simple working way to evaluate such kind of graph.
  At best I’m tempted to evaluate each node once per evaluation, starting from leaves. But it seems to not take care of the cycles.</p>
  
  <p>I doubt I found the correct keywords.</p>